Introduction:
On the surface the moves are similar, both moves are a 12 frame while stand move, both KND on hit, and both can wall splat (under certain conditions).
Additional Information:
During the change from Tekken 6 to BR, WS 1+2 no longer can be used as a wall carry tool. I'm not sure why they made this change as in Tekken 6, b+2,1 was the preferred carrying tool post bind, due to total carry and consistency.
Pure Speculation:
AFAIK there were no insane wall carry combos that included WS 1+2 so most likely this was a nerf to close range, wall oki. It's possible that, at max range, Dragunov could bait a whiff and at the max wall splat range for WS 1+2, it could be abusable, but realistically I can't see this happening or being practical at all.
Strategy:
Since WS 1,3 is i12, Dragunov can punish any close range, wake-up low with WS 1,3 making his low wake-up punishing a guaranteed wall splat. For this reason, it's not in the opponents favor to wake-up 3 kick while near the wall. The good news is that it's possible to bait out a wake-up 3 if they feel that whatever you just whiffed is punishable. This is due to wake-up 3 launching on CH and FCD D+3 launching on clean hit, if an opponent sees an opportunity, they'll most likely take it as risk versus reward is normally in their favor.
Going more in depth into the frames, wake-up 3 is normally is -12 on block while FCD D+3 is -14 on block. That means that FCD D+3 launches on normal hit and is launch punishable by only a few of the cast (namely Bob, Raven, and Kazuya) making risk versus reward tremendously in their favor. Once you factor wake-up 3 being only -12 on block, making it unlaunchable by all of the cast, one can see why wake-up 3 isn't that bad of an option.