Why does the Bowhead take Capital class rigs but can not fit any other Capital class items?
CCP how about you decide what class this ship is to fit? Either give it Capital class items or remove the Capital class rig and make it fit Large class rigs!
Freighters are highly specialized and thus have little to no fitting room. You should be thankful for what Bowhead has.
If anything, i think that all freighters would be better with a couple capital rig slots - more fitting variation and (more importantly) higher demand for unpopular capital rig types: warp speed, cargo capacity, agility etc.
P.S. Orca should have capital-sized rigs as well, imo.