Conditions- Speed Equalized with no flight only ground to ground H2H punching each other . No sun dip etc.
How Damage is Dealt/Taken - Superman's punches can hurt/affect his own durability like how any other character(even normal humans in Real Life) punches can affect and hurt themselves pretty badly.
Jirou Striking = Planet Stopping Knocking Technique. the Knocking technique will be treated as Striking feat(not as special technique which depends on nerves of planet), a (Punch)Tap capable of Stopping Toriko Earth. [No arguments here]
Superman's Striking is how writers usually portray him. Not the Plot based version which can punch reality, who Survives attacks which should kill him just because he is Superman. Basically a no non-sense Superman.
1.Post Crisis Superman
I am siding with Jirou on both accounts because of his Knocking Feat .