I think hidden is better, by leaps and bounds. While showing growths - on an objective level - is a nice feature for some, it’s also harmful and I find the cost higher than the reward.
tl;dr: If I trust the developer, seeing growths doesn’t change anything; if I see them ‘bad’ units are at best a chuckle before benching; and whether I think a unit is bad isn’t accurate to the game’s reality. Not knowing chances creates interest, unlike how not knowing numbers creates rage.
Unit Balance & Archetypes inform growths
For example, if the units are actually balanced against the game, I should be able to beat it with most combinations of units. If I know a unit’s got an 80% and keeps missing it, I’m going to be upset, but if I don’t know that, then I have nothing to get mad over as long as they’re getting stats. I may assume a character has growths that are nothing like they have, but because the growths are random it’s entirely plausible and even normal that I will get the unit’s 10% growth as my first level and not see their best growth hit until their 3rd and 4th levels.
Secondarily, a lot of unit archetypes have growths heavily correlated to their bases, like, Myrmidons have 5 / 30% strength and 10 / 60% skill and speed. They just will, that’s how Myrmidons work. Those attributes are what define the class. If a unit bucks the trend, it will probably show me that it bucks the trend after a few levels and I can either keep with them or swap them out - over the course of any reasonable campaign, the developer already has to give new units that are viable to swap in, or chances for weaker ones to catch up.
This all comes down to, in essence, having trust and faith of the developer: They are not here to troll me. The level 5 unpromoted unit in chapter 15 of 25 has comparatively high growths, not total trash ones.
That, of course, comes from how the developer wants the player to beat the game. It’s not adversarial, despite the fact that they are the one putting the challenges in front of me.
Effects of growths and showing them
Because of that, showing growths feels a bit like the developer saying either they don’t deserve that trust, or that something is weird with many of the units.
It’s also the case that growths… are actually not that important a lot of the time. If you’re thinking about an average, 5% growth maps to 1 stat per 20 levels - and most games do not let units get to 20/20, it’s way more common for the game to end at L10 promoted - and units don’t always get to L20, and very few join at L1. So a 20% growth difference can easily map to only average change of 3 points because the unit only gets 15 levels in a playthrough - very significant, but also not make-or-break for a given unit if it has other stats.
People can and will see a unit who has 6 / 20% speed and say “oh bad unit” even if that unit is actually one of the best units in the game from their other stats because of what kinds of enemies you deal with. It’s incredibly disheartening to watch people pivot away from a character because they check the growths - that frequently barely matter! - and even worse, these snap judgments are wrong plenty often.
Like, consider: Roy is actually a competent fighter. He’s not got excellent combat, but even on Hard Mode he does not struggle to hit or deal damage or risk dying in one hit often. Yet people will tell you that Roy has bad combat, which comes from three things: He has 5 move in a game that’s loaded with good cavalry, his promotion time is obscenely inexcusably late, and he must seize every throne so it’s “inefficient” when he’s fighting - or even walking on his own because of said 5 move.
In a similar way, look at Blazing Blade - even in Hard, most enemies will have attack speeds less than 16 up until the actual final chapter, so the fact that a given unit is slow doesn’t really matter. Oswin is a fantastic unit despite having 5 / 30% speed because that’s actually enough to double.
What if the developer's messing around?
Let’s look at the other end - If the units are not balanced, then seeing growths… lets me know that? And then I don’t use the unit. What was the point of giving me a unit that has garbage growths if I can immediately see that it has bad growths and therefore no payoff for use?
If units don’t have growths implied by their class or bases, then I find this out without investing anything into them and decide if I want to use them or not. Frequently, this isn’t meaningfully different than the case earlier, however, because whether I use a unit initially is dependent on how many units I have and what stat profiles those units cover -
No matter what the unit’s growths are, if I have zero units with Res and you give me a unit who joins with 10, I will use that unit when you throw eight mages at me. They’re the only unit that can perform a job that I’m in need of.
Similarly, if you give me an armor knight in a chapter that’s full of Hammers, I’m not deploying them, and probably even if I know the unit has turbojacked growths, because using the unit will be such a total pain in the ass that it doesn’t seem like it will be fun, which is what I am ostensibly playing a game for. But if you give me a ranged attacker in a map full of choke points, that’s much more palatable!
One of the most fun times I ever had with units was with Eliwood - his growths, being 30~50, make his stats at any given point in time incredibly chaotic. Sometimes he’s the best unit and sometimes he’s the worst unit, and that’s really neat. But if I saw his growths, I’d be put off by this trait! He doesn’t do something well, and that means I have to constantly play around his progress. Which is actually really nice.
It’s also sort of the case that, generically, having randomness and chaos is one of the only unpredictable elements - just like hit rate - and having these is very good because it creates slack that prevents the game from becoming a puzzle where you have to figure out the intended solution.
1 to 12 preferred hiding chances
FE1 to 12, the only other piece of hidden information about units is how 4/5/8/9/10’s skills exactly work - the proc rates are hidden. Just like growths, that’s also a random chance of an event occurring.
Most skills that are consistent, and the ones that actually affect damage ie. Counter, Cancel, Luna; or mid-turn recovery ie. Sol, do have their actual influence listed.
The only ones I know that don’t give information like that are Renewal and Corrosion, which say “a set amount” and not mentioning that the durability damage scales with user level respectively.
But then 13 made it so that every proc rate is exposed! And yet, they still hide growths.
Because at the end of the day, the thing that defines Fire Emblem is its simplicity and the thing that seeing growths does is make things complicated. It asks you to judge how much growths matter, how much experience units will get and how much that means their growths affect their stats -
But the point has never been about planning around the future. You don’t know the plot in advance. The characters that you get, what they wield let alone what their stats are. That’s really cool and interesting. While tactically the game is about simple, understandable stats and formula like X = A + B - C, Fire Emblem has always been “Oh, what will happen on this journey” - and that requires not knowing things.