A. If the Thors remember what their uru hammers can do, and remember the abilities written (that seemed to have been forgotten by the writers of Thor sometime in the 1980s), they easily win and defeat the Supermen.
B. If the Thors however think their uru hammers are blunt weapons, decide to attack in a stupid manner (like the Hulk would if he carries a bludgeoning weapon like a hammer or bat), or just resort to blasting away with damn lightning, then the Supermen will easily win and defeat the Thors.
It’s A or B, fully dependent on the Thors being ancient gods with exotic powers, or non-green Hulks with long hair that think everything is ‘smash.’
If it is the former, the Thors win (and I can argue easy ways they can win that would re-destroy Krypton all over again ...Thor was once depicted with crazy abilities, what I would call ‘pre Crisis Thor’ if he was in DC).
If it is the latter, the Supermen win (and I can easily argue myriad ways they can annihilate Hulk-wannabe Thors that tromp around thinking the object they hold in their hand is a fist rather than something that could make a Green Lantern literally green with envy).
A. If the Thors remember what their uru hammers can do, and remember the abilities written (that seemed to have been forgotten by the writers of Thor sometime in the 1980s), they easily win and defeat the Supermen
As they'd be fighting to the best of their ability.
I personally would have preferred opening of portals to unknown and unknowable dimensions that tear them apart, or maybe stealing their souls, or maybe leaching their life spirits, or even blinking to the distant past and destroying Krypton ...and ensuring no little babies escaped in tiny space ships.
Don’t get me wrong - I think the whole Kryptonian mythos is cool. However, a high level Thor written by a writer who actually remembers half of what the character can do, will wreck all but the highest level Kryptonians (and by high level I mean those with Prime in their name, or with imp blood and such tripe).
Every. Single. Time.
However, if written as berserker types who just want to smash (hence my ‘non-green Hulk wannabe with long hair’ moniker), then they would stand no chance against an average non-jobbing Kryptonian.
Every. Single. Time.
It all depends on how the Thors are written to see their hammers ...as an omnipotent weapon of the gods, or as a heavy bludgeoning object that at best is equivalent to Hercules’ golden mace (and at worst a really heavy baseball bat).
As Thor USED to be written ...not at all! He could do all that quickly.
Throwing the hammers is still a ‘smash’ technique. At least 3 of the Supermen are fast enough to outmaneuver and outfly the hammers, and take out the Thors. Throwing the hammers is still a smal technique ...just (i) ranged and (ii) by remote control.
Sending the Supermen to the heart of a red giant is something old Thor could have done easily (while making himself intangible to any physical attack).