So I’ve spent like an hour trying to work out how Roberts’ stats are calculated (because the numbers do not line up when I try the prescribed method on Triangle Attack). As it turns out, basically every FE site I know screws up the process one place or another. Either way, here’s what I found.
Enemy Stat Calculation:
Stat ranges are calculated as following;
- Lower Limit = Class bases + (ClassGrowthLevelsGained7/8 rounded down)
- Upper Limit = Class bases + (ClassGrowthLevelsGained9/8 rounded up)
… where LevelsGained = DisplayedLevel-1
Promoted units are treated as having gained an additional +19 levels (Triangle Attack erroneously states this as +9 on Normal; this is wrong; it’s still +19).
The game first takes ClassGrowth*LevelsGained, the average stat amount, and multiplies it by a random value between 7/8 and 9/8. The resulting number is composed of an integer and a decimal. The integer is the number of guaranteed, whole, stat points, while the decimal is treated as a growth rate and is rolled once to determine whether or not an additional stat point is gained.
For example, if the number was 8.34 after randomization, then 8 stat points are guaranteed and there is a 34% chance to gain an additional point.
Hard mode gives every enemy on the map, except non-reinforcement recruitables, additional levels. This is dependent on the chapter, and can be found here. These levels use the same formula as above, where they take the place of LevelsGained but otherwise are the same. More importantly, Hard Mode levels are calculated INDEPENDENTLY of standard levels, and as such create much more variance in enemy stats than if they were merely added to LevelsGained, since now the growth rate portion of the amount of stats gained is rolled twice and not once.
For most bosses, they get nothing out of the natural LevelsGained, and only gain extra stats from Hard Mode bonus levels.
Roberts runs completely different however. All other bosses are set to the same level in both the Character Editor and Unit Placer; this causes no issues and they get 0 LevelsGained since they are already at the correct level. Roberts, however, is set to Lv2 in Character Editor and Lv1 in the Unit Placer. This causes the game see that his base level is not equal to the level he spawns in as, and as such levels him up until they match. Since 2 > 1, this causes him to loop around and get 19 levels instead as his LevelsGained component. On Hard, he also gets the +9 level boost assigned to all enemies on the map. This is responsible for his massive stat variation, as he, like all other generic promoted enemies, have a larger stat variance range due to running the leveling calculation twice; once for LevelsGained and once for Hard Mode bonus levels.
Roberts does also have personal base stats, which after his randomized stats are calculated, are then added on top of them. They are:
HP: 8
STR: 4
SKL: 3
SPD: 2
LCK: 6
DEF: 2
RES: 0
CON: 0
TLDR: Roberts is a generic Lv1 Paladin with the above stats added on top (he still gives bonus Boss EXP).
So, @AthenaBaer, if you want, you can add Roberts to the pool of bosses; just know that he is effectively a generic enemy with extra stats, unlike other bosses who have fixed stats on Normal difficulty.
Playables 
Because this kinda thing feels more like William because he was left unused in the final game. Or maybe I’m just really dumb 
That works too.
I’ll ponder on that, since Willy-boy wasn’t intended for the final release, plus if this is any indicator of how whack he is, then it’ll be a hard sell, but we’ll see where I land 
