Without getting into whether it's luck or some sort of skill that just happens to be especially mercurial (I tend strongly towards the former), you need A TON of evidence to be able to say someone's anomalous homerun per flyball rates are real. Like 500+ innings. In the vast majority of cases groundball rates are a sustainable skill, homerun rates on flyballs are very much not.
Despite wrapping year 3, Wesneski is only 190 innings into his career. So just like Lance Lynn gave up an astronomical 44 dongs in 184 innings in '23 and came back fine in '24, our default assumption should still be be that Wesneski's issues are not permanent.
And dongs aside, Wesneski's numbers are pretty solid. He misses bats, throws strikes, and keeps the ball on the ground. He's got a wide enough arsenal where he doesn't have a strong TTO penalty to his peripherals (though boy does he to his ERA). There's nothing crazy here, no "he's secretly a star" stuff, but league average starter or 8th inning guy both look very reasonable.
Assuming Assad is the fifth starter next year, I'd have Wesneski in long relief and the guys who ended the year hurt opening at Iowa. But honestly I have more faith in Wesneski's dong problems being a mirage than I do in Assad being able to manage an ERA a run lower than his peripherals without inducing a bunch of soft contact, so I'd be totally down if spring training results swapped those roles.