That's a logical fallacy on the order of cows, legs-n-animals. You're assuming that there are only three classes of form factors as well.
Nope, they'd be more of a bastardization of the Desktop family . . . on a rope.
Maybe Bolo Macs? Two lumps, desktop & floor, tied together with a rope, the third lump being the monitor oon another rope . . .
. . . maybe like a Minitower made of bubblegum with the I/O half of it stretched to be on the desktop and the PSU section left sitting on the floor.
They can't possibly be AIOs as they come in two pieces . . . CPU/PSU . . . Modular Macs?
) There were plenty of Video Upgrade Cards for the LC Series, not to mention Sound Cards and rudimentary VidCap solutions.
For Low Cost Macs, and all early and home Macs, AppleTalk was the de facto standard of that era. The reason for the ubiquity of the EtherNet Card was the adoption of such Macs in droves for educational use with Servers, where AppleTalk Networks would bog down badly in a classroom/school environment.
Only Apple, hucksters of the disposable Jobsian Appliance, insist that ports are a mode of expansion. Slots are for expansion, ports are for peripherals, at least until very recently.
Note, my Micro ATX Dual Core ATOM NetTop board from Intel, it has a PCI slot!
All IMHO, of course! :approve: