Switch cartridges come in 1,2,4,8,16 and 32 GB capacities. Below are the file sizes for the various MM games:

Mega Man 128 KB
Mega Man 2 256 KB
Mega Man 3 384 KB
Mega Man 4 512 KB
Mega Man 5 512 KB
Mega Man 6 512 KB
Mega Man 7 2 MB
Mega Man 8 235.42 MB (PS Store)
Mega Man 9 63.06 MB (PS Store)
Mega Man 10 143.73 MB (PS Store)

Mega Man Legacy Collection 289.6 MB (PS Store)
Mega Man Legacy Collection 2 4.96 GB (PS Store)

Mega Man 1-10 Game Size Total 446.46 MB

MMLC 1&2 Total Size: 5.25 GB

Based on the PS Store sizes for MMLC 1 & 2, if Capcom did absolutely nothing, they'd have to use an 8 GB cartridge. With some work, they may have been able to use a 4 GB card.

It's amazing to me that they work so hard to balloon the footprint of games from 20 and 30 years ago, yet will do nothing to keep file sizes down. Capcom has to employ people to make the Switch release, so while they're paying them anyway, why don't they allow them to do something useful. I don't know if it's just a corporate thing to never use even the easiest solutions to problems. If they want to cheap out on game cards, that's fine, but don't say it's because there's no way to fit it. too much work, etc.

They can pay dozens of marketing people, but they can't pay one or two programmers for a few months to think about the problem and come up with a viable solution? Sounds like radio.

So 446.46 MB are the games. 4.8 GB is something else. No way to reduce that without diminishing the product? Okay.

I wonder about the upcoming Street Fighter Collection. If they can find a way to make one of the 3 MB games into 3 GB, I'm sure they will.