"I could be wrong, but I don't think Win98 was every made available on floppies"
They ALL were. 98 Gold sized cabs are 1,716,224 to the byte which is the same size created when you format a floppy with 21 sectors per track and with a cluster size of 2,048 bytes with one directory sector. YOU then copy the cabs over onto the floppies your own self, Microsoft is not selling anything.
So for 98se with 1,802,240 sized cabs you run with 84 tracks and 64k sized clusters and one directory sector and get that same sized floppy. EXCEPT very few floppy drives can make this disk and nobody used the above method much anyway so 98se on floppy was a pretty much a flop.
"I know Win95 came on 13 specially formatted floppies."
Yep, 1,716,224 as before. Same for 95b BTW, they gave up on floppies with WinME I guess. The 13 disk set for 95 is a 95a light version where you don't get a lot of bells and whistles. It was mostly help files that they cut out to get the count down so low even for 95a. But IMO, 95a is not worth using if you have 95b around.
Use fdformat to make those wacky formats -
It comes with some instructions but to save time and frustration:
fdformat a: c4 d16 f168 = 1,716,224 free bytes 95b 1,676Kb
fdformat a: c64 d1 t:84 n:21 h:2 = 1,802,240 free bytes 98se 1,760Kb