Squads are flexible and yes, even in the case of mercenaries if all of the leaders fall, then the squad collapses and that is wholly intentional by Toady's own design with mercenaries already, hence you would pad it out with more than one leading soldier dwarf ideally well armed & trained and all the remaining 'minion' squadmates would still be in a combat situation into close proximity or far away for it to not matter before the player re-assigns them.
Let me rephrase myself* trolls are [SLOW_LEARNERS] to all effective purposes is what i meant, and do not have the intellectual capacity (skill learn rate -50% and can't do unspecified labours) of full trained persons already, therefore are treated as intelligent livestock, calm down as i can see you're getting worked up over it. I don't exactly understand or follow what the physical description of has to do with your complaint about a lack of a detailed entity file as a 'mistake' as details outside of physical body dimensions & tags are completely arbitary.
I don't know how you concluded that I was getting worked up about anything, now I am getting worked up about how people said I was getting worked up.
[SLOW_LEARNER] is basically a shorthand for the set of tokens that control the speed of learning, all it means is that the default learning rate of all skills is set to 50% of what it normally would be. There are no special mechanics associated with that token, the situation as far as the AI and the game mechanics are concerned they are identical to other intelligent creatures, the only difference is the rate at which they gain skill points from working.
The situation as regards
[CAN_LEARN] pets is bugged in that while said pets do work using the same AI as everybody else, it is only the work that is on by default which tends to be thinks that have no skills; that is because the interface does not change from pets that cannot learn to pets that do; meaning they have in effect a labour list but one we cannot access. This situation has nothing to do with the tokens *of* the learning pet, you could make them as seemingly super-clever as you want or as stupid as you like in terms of their raws and it will not change the situation.
As for the rest, I was simply stating that I don't think that the devs did a very good job of defining animals VS people and a major factor in this happens to be the way that they made regular creatures actual appearance derive directly from the creature file tokens with entity creatures placed separately. I would have been better for them to have had all creatures actual appearance in the game defined by the entity files and having actual civilisations procedurally emerge based upon the tokens found there.
*[Poor explanation on my part]
Yes a wizard could have a cap on summons, but that is not a concrete rule if you can summon a unlimited amount of minons if magic procedurally and unpredictably generates its rules that way, it also cohesively keeps them all under control and for lack of squad system the personal party system works in its place under much the same rules that you couldn't have a full roster of companions and permanent summoned entities.
Its not a different squad, its the same fortress military squad/party in the original detail, im not sure how you became confused, it deals a critical nerf to potential battle wizards too enrolled or played directly in a adventurer format by the player. A lot of it is also about keeping these beings under control so you don't have maruading units where they shouldn't be, hence the suggestion to pair the undead with a vampire (who needs no sustenance) on permanent duty & loosely attach units.
If you want more unit attachments, just make new militia squads or expand the sizes of miltias in the entity file, or build your charisma in adventure mode.
Procedural generation does not have magical powers FantasticDorf, I cannot produce anything that is not programmed deliberately or otherwise to produce. Being able to summon an unlimited amount of minions is not something that should be allowed to happen, as a rule there must some limitation on the number of creatures that can be summoned whatever it's exact nature. It is also something that cannot mechanically be allowed to happen for obvious reasons related to memory.
There are two ways we can handle summons in relation. One is we can ignore squads altogether and have the summons operate in an individual relationship to their summoner, or some other character. They will follow about and defend that character, ignoring his squad status since it does not matter. The second option is to have the summoned creature join the squad of the summoner as an extra member, potentially going over the squad limit. The third option is to have summons form new squads, this creates a problem in that we end up with a clutter of small squads running about.
I favour the second option, making the summons extra members of the squad in a special case, so the squad can go over the maximum size through summoning but the player can make it go over that limit otherwise. We can however assign existing summons to empty slots in existing regular squads like they were anyone else. Other things that aren't summoned in the thick of action (wizard constructs, regular undead) should just start off as normal creatures and be assigned to squads normally.