EB units with BI don't have shield wall or swim!

[antisocialmunky]

Does the AI use it to make bridge battles less horribly lopsided for the human player? Like if they didn't try to push every single unit over the bridge anymore?

Yes and no.

Yes, if units can swim across and flank you because the AI lines them up on the opposite bank and then swims across at different points. No, because most 'heavy' infantry can't swim and if I have heavy infantry on the banks, the AI is screwed. Though, swimming Gaestrae would probably give the celts a good prospect for victory. Also no, because if an exhausted unit is swiming, it'll start drowning... Chances are better than trying to rout past your units but still.

[Conqueror]

It does force the player to spread his own units out instead of concentrating them all on the bridge/crossing point. If he only has a small army then this might be significant, but a player defending with a full stack is going to butcher the AI either way.

[Bonny]

Question though: if those attributes are put into a 1.5 build, does it crash or just ignore them or what?

It crashes on startup.

[Zarax]

It should ignore them, at least id does with formations and swimming...