I'm curious as to how MCU Iron Man would stand a chance against 616 Spider-Man without the Iron Legion.
MCU Iron Man doesn't have anywhere close to the same strength or durability as 616 Iron Man.
Meanwhile, 616 Spider-Man has mastered his powers, has greater strength feats, has combat speed and reaction feats unmatched by anyone in the MCU that isn't Quicksilver, and is actually skilled in h2h combat.
If MCU Captain American can use his lower-tier superhuman strength and h2h to knock around and daze MCU Iron Man, then this should be a cakewalk for 616 Spider-Man.
616 Spider-Man would be like combining the physicals of MCU Thor and skill of MCU Cap into one character. And, we know how those fights went for Iron Man.