There's probably a version of Iron Man out there that's a combination of Vanilla Iron Man (better dashes, actual tri dash, double jump) and Ultimate Iron Man (air dash cancelable normals, glide feature, better specials) that is top tier as hell.
The only keep away that Spider Man struggles against is Morrigan and Zero mostly because they flood the screen with hitboxes which means navigating them with straight ziplines is difficult... so basically every character against those two hence why they are god tier. Any other zoning character gets whooped by Spider Man (so Dorm, Chris, Hawkeye etc) because of Zipline. And Spider Man actually has Zipline pressure along with weird overheads. Spider Man is legit high/upper mid tier character. Spencer is just the gorilla version of Spider Man where he has some gorilla hit stun normals that he converts to big damage which means him easier to play. Spider Man has small hit box attacks and low hit stun meaning you need a lot more finesse to play him, probably why he never got any popular in the States. He's around Deadpool good and Deadpool made top 8 at EVO now.
naaaaah, deadpool is way, way better than spidey for a whole lot of reasons. the biggest one being he has an actual presence in terms of zoning. spidey puts his body out there and throws a web ball really slowly at best. when someone jumps away from spidey he can't do jack shit about it. when someone jumps away from deadpool, that's a
good thing for him. he's been massively underrated for awhile and is in a group of competitively viable chars that i think have been left at the wayside since the game got "solved" faster than they could be explored. so like, spencer/wesker tier, roughly. spidey's a bit below that group, which mega sucks since he's so fun to use. but hell, who knows- ryanlv can make chun into a disgusting monster via proper team synergy so maybe spidey has something like that going for him in his runaway strength.
as for the 'keepaway' chars you listed, the only one that actually "loses" to spidey is chris and that's pretty arguable in itself. spidey doesn't have a way to make chris really respect him so it's this weird battle between two chars who don't really have a way to deal with each other effectively. when i say keepaway i mean magneto, deadpool, modok, doom and whatnot- chars that have effective movement and ways of stopping an airborne char from farting around too much.
and yeah, i know about zipline mixups. that's why i specifically singled out his lack of ability to actually force them to sit there and block it. he doesn't have the same luxury that spencer does in a lot of ways in regards to that, not only in terms of hitstun but also in terms of hitboxes, speed and fishing with random chin checks (in terms of doing counterzoning grapples/frame trap grapples). he can't force someone to eat mixups like spencer does because he doesn't generate pressure in the same way spencer does via dashup jab or jump->downforward zip. people aren't scared to do shit against him and they have no real reason to be scared. you're really overestimating spidey's zipline- that shit is really not that good
as for iron man, the only thing he really needs to be top tier are a real airdash, a real dash and a real launcher. if his launcher worked from max range cr.m or if his st.h came out faster/went just a bit further so comboing from cr.m worked well he'd be really really disgustingly good. when marvel comes out on pc i'm hoping someone figures out how to modify that stuff easily so i can show a quickie example of how absurdly silly he'd be just airdashing around pressing df+H. his support value in unibeam, TACs and a framekill DHC/THC is already pretty damn good- the only thing he's really missing is a safe DHC in that sense.
if iron man had a glide though, holy shit would he be super annoying to fight. like at least dr. doom levels of annoying. dude should've totally had it since he ended up having a wack ass airdash. it'd be fun to just glide around pressing j.s/j.H/df+H at dudes all day