Special teams is a limited play, potentially big impact part of the game. I can count a lot of times in the past 25 seasons that Steelers failures on ST has done us in. An All-American K/P returner that can give you a few gadget plays is worth it. Speed? He has enough. Many absolute burners have failed as returners because a good returner is much more than speed. Fearlessness, ability to see developing holes, balance, reliable hands under pressure are all more important. Remember, the guys trying to make the tackles have their momentum going in the wrong direction--make them miss and 4.47 speed is plenty to get you to the end zone. Hell, if his college TDs are only returns to the opposition's 25-15 yard line in the pros I'm all in.
And as for being a receiver, he's good enough to be one of the "other guys". I mean think about it. Your top 3 WRs should catch at least 180 passes; your top 2 TEs, 100 passes, and; your RBs, 50, at a minimum. That's 330 receptions right there. How many more are there to go around? The other guys catch 1.5 per game collectively, you're at 354. At 30 attempts a game, that's a 69.4% clip. The only way to put those numbers up is throw more than is probably desired (like 40 times per game). Arizona (behind a lot) led the league last year at 38+, Rams next at 35+. With our top 3 WR, 2 TE, and 2 RB, we have a good core group of pass catchers. If Wetgen is an above-average returner for us, 8-12 receptions on the season and a handful of successful jet sweeps is enough from your 5th or 6th WR.
Perhaps R. Wilson should be our deep speed guy? If he can't run routes, as many claim, just give him a route tree that is limited to using his speed, which is pretty good. A guy catches 3-4 bombs against man the safeties start to notice.