I'd say stomp, then I look at Leon's speed, all Leon has to do is land a shot with the rocket launcher or a few magnum shots to win, but since the Courier has luck on his side, there's a high chance Leon may "miss" his shots, late game Courier can also CQC Super Mutant Behemoth's which can hit w/ 0.321 tons, if we convert the building level scan energy joules to tons of TNT.
Assuming this is late-game Courier; each attack Leon will be dealt will feel like a truck. Leon will only be able to harm them with his high-powered weapons & explosives; Leon's death cap is also at 0.364, but since he has his equipment, he's got a 30% damage reduction with the vest, meaning the cap nears out at 0.473 tons.
. . .
That is if the Courier manages to even land a hit, that's where Leon's vastly superior reaction & combat speeds come in, he'd likely end up using a flashbang to get away when he realizes his opponent is strong. The Courier has a faster travel speed, but Leon can definitely keep up in CQC, assuming Courier's luck doesn't make Leon slip up. In CQC, Courier is definitely getting speedblitzed, when Leon realizes hitting them isn't going to work, he's going to work up-close with his guns.
Not to mention Leon's superior lifting strength means he can out grapple anything the Courier tries. (he could most likely disarm them too, since Leon has knowledge, he'll know about Courier's lightspeed weaponry and to disarm them or stick to CQC so he can dodge their line of fire completely), knowing of their supernatural luck, he'd most likely take a gamble with the rocket launcher too. Leon. . Also has a laser based weapon if you count the P.R.L 412.
IF this is 2010 onwards Leon, I'm voting Leon, since by RE6 & the late movies, he's already
implemented,
numerous,
ways of utilizing his weapons in CQC; ultimately, he'd just speedblitz the Courier and put a couple magnum rounds in him, Courier's luck isn't always 100%, so eventually he will slip up, since Leon will basically see almost everything the Courier throws like it's in super slow motion.
Maybe it's still a stomp? Idk-