Re: Fat and shallow
Bass/kick drums are not the heavy lifting in the drum world wrt lug clearing, since they typically only get hit dead center so preferentially excite just the fundamental and not the sundry higher pitch overtones. A Fat/shallow aspect ratio should have stronger coupling between batter and resonant head. You don't say but I ASSume both heads are mounted.
Regarding one head vs two heads mounted.. The larger diameter 24" will sound a lower pitch fundamental note than smaller diameter kicks, all else equal. Two heads mounted will make a higher pitch fundamental note than one head alone.
YMMV..
JR