Well...Supes and Surfer in the same team is always a deadly combo...
I'll just have WWH's fight with Sentry be the deciding factor for hulk vs Sentry. They duke it out...both revert to humans and proceed to slug it out while the other 4 continue to fight.
To be honest Ion-Yat does not impress me. On paper he sounds like a beast, but we know Ion is not as powerful as it used to be, and I haven't seen much of Yat.
Superman and Surfer blitz the crap out of Thor. Then they proceed to double team Yat. or perhaps Surfer simply sits back and soaks Supes with yellow sun energy.
Sodam Yat went toe to toe with Superman Prime for an entire issue, and fared better than nearly anyone else that went after him (that didn't include speedforce dumping or a red sun).
Putting him below the Hulk is a pitiful insult. Also, Superman ahead of the Surfer? What the hell?
Odin Powered Thor > Surfer > Superman ~= Sodam Yat > World War Hulk > Classic Thor > Sentry
Theoretically speaking, Sodam Yat should be approximately Superman's equal, if not greater, even without the ring or Ion power.
Judging purely by his current showings (which aren't much), I'd say he fared about as well against the Anti Monitor and Superman Prime as New Earth Superman would.