I typically like higher growths to feel less bad. So for my hacks prepromote max stat is 25 instead of 20, and promoted can go upto 40 instead of 30. Classes that heavily favor one stat usually have it at a max of 40, while mediocre stats are 34-36 and like the worst of the worst is 28-30. So only a slight improvement but you shouldn’t gain stats in these anyways. Oh also HP is 80 prepromote and 120 promoted. Most (anyone) shouldn’t reach these, but High HP is fun to see anyways.
With that in mind my stats growths are usually in the 40s+ HP is usually 70+ with some people at 100+.
My MC has HP:90 Str:70 Skl:60 Spd: 65 Luk:55 Def:45 Res: 45 Mag: 45 sword lord with magic prf.
So his HP will almost always go up and his Str/Skl/Spd will typically levels as well. He’s my strongest unit in game and his stat reflects as such. Also when I test run sometimes I think “jesus christ he’s a monster why does he do so much?” And I forget he’s the MC and the ONLY one who can do this.
Fighter has HP:115 Str:80 Skl:55 Spd:50 Luk:35 Def:65 Res:15 Mag:10
So a little more minmaxed, chance for HP to level twice with his Str and Def also having a good chance to level, but with stat caps of 25/40, he’ll need higher Skl/Spd to keep up so that’s boosted to 50 for a more likely chance to level it.

And that’s him with a base speed of 6 at lv1. So he got good levels but still can’t double some and is keeping up. Even so he can double some units without trouble and it shocks me when he’s smacking someone for 20damage.
My “jagen” (Oifey) HP:135 Str:50 Skl:65 Spd:45 Luk:35 Def:65 Res:45 Mag:35
So he gets decent but not amazing growths to still keep up with the team if you so choose to. He starts at lv15 in a hack where max is 40 and levels carry over through promotion. So by the time he can start getting EXP he’s behind everyone but still solid. Also getting his PRF lance which grants Aptitude so he actually will turn out really well if it’s used smart. But that will take a while of holding onto his weapon not using it.
Finally guess what class this person is - HP:65 Str:5 Skl:45 Spd:80 Luk:70 Def:30 Res:70 Mag:50
If you guessed something something probably a mage, your right. She’s a cleric with access to light magic prepromote. So she’s quite minmaxed with Very High Spd/Luk/Res to take on mages, with a chance to level magic as to not outshine your other ACTUAL mages. With low defenses and skill, but her light magic makes up for it mostly, she’ll still have a tougher time hitting people later in the game which is perfect because she isn’t built for combat, but you can use her for it without too much trouble. Even so I still gave her HP a 65% to grow, because later with enemies walking around with 25-30str and weapons damage will spike really hard. So she needs it to survive one hit, maybe.
So basically it depends on what you want from your games: My growths for normal units are 400-420, while my MC and “jagen” and other OP units is 475. But that’s to compensate for the 25/40 stat caps I have planned. If I was going normally 20/30 I’d drop these by like 20 across the board.
If you want to check high growth rate games look at Awakening, Radiant Dawn, Some of FE Fates. Lower growth rates are like FE6, Echoes, FE12 that stuff.