Im currently at war with the Hissho and while the AI seems to be capable to attack and defend, its heroes are flying around in small scouts, instead of leading the fleets, which seems to be a misbehavior to me.

I have not done a single hero build with the adventurer skill tree so far, could it be that it makes sense for adventurers to fly in scouts ?

Havent made that either, but one Hero with adventurer currently flies around my empire, noticed nothing so far. There is also one Commander/Administrator in a scout, which definitely doesnt make sense.

I've definitely observed that as well, the AI loves putting its commanders in one ship scouting fleets using the standard scout ship design from the start of the game. I mean, those ships have their uses, but it's 125 turns into the game already! You're fighting a total war for survival against the alien menace, surely your commanders would be best utilized commanding the toughest fleets in the most pivotal battles, not puttering around a mostly-explored galaxy in a small scout ship!



Maybe if the hero helped them scout out the enemy's back field, that'd be useful, but it feels to me as though the AI puts them on the ships for valuable experience and then doesn't sort them over to the warfleets, assigning too high a weight to the scouting fleets. Granted, getting your guy's ass shot off tends to be a huge experience booster, but still...you gotta use that experience sometime.