Bit of a thought I had and decided to expand on after watching the three houses trailer again.
What if every unit in the fire emblem games is actually a unit of soldiers, and the lead unit is the captain.
it would give some realism to genealogy because one horse taking up what is essentially a 10km^2 space is pretty unrealistic.
And the healers are mostly religious because they can make the soldiers in the unit pray, boosting morale and to some extent regaining their health.
This might be a bit of a stretch, but it's something interesting to consider.