This is a rather challenging choice. While both actors were very well established as action stars in the 80s-90s, obviously Stallone got a much better start in mainstream cinema with Rocky, while Arnie had to wait for other opportunities since most of Arnie's earlier movies weren't that good to begin with. By 1984, Arnie got his time to shine in the Terminator while a year later, Stallone's Rambo First Blood part 2 came in. To cut things short, Stallone had a better start, Arnie had a much better ride in the mid-late 80s to the 90s. However, 2003 and T3 Rise of the Machines, Arnie had to stop acting for a while to become the Governor of California, while Stallone still did some movies like Rocky Balboa and Rambo 4. Its a pretty hard decision, but if i have to use the 90's as a decent outlier, I'd definitely go with Arnie for this one. Arnie's movies were much more recognized and more delightful than some of Stallone's unfortunate entries in the same time period. Like seriously "Stop or my Mom will Shoot?" vs Arnie's "True Lies"?
So Arnie. Besides, Ahnuld is much more fun to make tributes out of. If the next CoD game or any damn game had Arnold on it, I'd be buying it. "PUT THAT COOKIE DOWN!"
OT:
1) A Quad Barreled Super Shotgun with the ability to create 3 other copies of itself that gives you the power of a QUADRUPLE QUAD BARRELS aka SIXTEEN BARRELS OR 2) A Rapid Fire Gatling Gun that launches miniature fighter jets that carpet bombs the target zone while crashing into their target, as its bullets.