One issue with increasing unit size and upping ship capacity to match to avoid dual ships would be units being stuck underground in coastal battles. Those issues is why I've stopped using higher unit values.

However in my current campaign attacking Carthage their reinforcing fleet has units stuck underground, with default unit sizes. Going into main_units and changing every entry under the naval_unit column for Car_* troops to greek_seven fixed the issue. But not something I'd stick with.

So I've been trying various ways to change the transports, and none have worked.

I've gone through naval_units and ships_dbs tables and no changes in either had any affect (trying to mod the transports to greek/persian/roman/egyptian_six). Would like to find a way to do it without modding main_units as that way it'll be compatible with most mods.

Not sure why it's doing this on Default unit sizes to begin with.