Super Surfthor Gauntlet

This is Superman, Surfer, and Thor merged into one being.

He has Superman interllect
Thor aggression
And Surfer multitasking skills

...along with their powers stacked.

Hyperion, Sentry
HP Doomsday
Alan Scott (the one that took on the JSA)
Starbrand
Justice League (Wonder Woman, Orion, Captain Marvel, Green Lantern Hal, Aquaman, Martian Manhunter )
Thanos
Superboy Prime
Superman Prime
Grandmaster
Odin (can't mess with Mjlonir)
Galactus (can't manipulate the power cosmic)

Where do they stop

They get flattened by Odin full stop.

Billy solos. And then wherever you want to argue they'd stop between Thanos and Supergirl

They never make it to Galactus though

Jiminy Crickets. Synergy+. Can I assume that by "Superman's intellect" this includes his creative power deployment? As such, Galactus stops him after a good fight.
Maybe I'll dig up my Synergy pic and top it with a Thor helmet, just to give some idea of what this awesome fusion could look like. 💃

This is going to be a ****ing beastly combo, that's for sure.