Mech Truck repair has never struck me as being particularly quick btw. Think it's mostly useful because it means you don't have to divert your Sturmpioneers away from the fight.
It's a bit under a vet 2 EF engi squad, but it's especially microless
and popless, which are very valuable traits in a late-game slog. With it and a vetted sweeper SP squad, nigh-dead Panthers will be rebuilt in 28 seconds. It's not something to rely solely on, unlike vehicle crews, but it combined with SPs can't be discounted (also for comparison, a fully vetted RE squad + vehicle crew will repair a Sherman faster than the Panther example by...like 2, 3 seconds).