I've seen double sturmpios used to great effect on many-a tight maps. Especially by top10 (premades and solo). They are not as burdened as people make them out to be. Later on you won't fight them as much, but they can still cause a world of pain.
3 models cost 90 MP
In early game they can take out 3-4 models of rifles and usually retreat (if they don't win that engagement) with 2 models. That's 60 MP for you, and 84-112 MP for USF. Given how REs are dogs*it tier in combat unless you get lucky (can happen), you'll have volks vs REs the next fight in most 3v3 maps.
Assuming that the player goes 3x rifles vs 3x volks.
Now volks are dogsh*t tier close range, hence why you absolutely need to keep them behind cover, and they'll win against all but IS behind cover.
But all in all, repairs are fast on OKW. Whether that's justified or not, won't comment as I've never ever played OKW competitively. But they are fast, no doubt about that.
Considering SPios after the 15 minute mark. I mean, they can equip shrecks, put away the sweeper. Double SPio is 16 pop, so it is on the costlier side (compared to the usual 10 for CEs, REs...), but I think they justify the pricetag. Might be overburdened in 1v1s as the combat is spread out across the whole map, but in 3v3s+, where it's much denser, they are absolutely disgusting how much damage they can do in a short amount of time close range.
Hell, Lady, you witnessed when my REs were firing point blank on a static, AFK, MG42 squad for 10 seconds or so, and only took out 2 models, until you came and shoo-ed them away. Spios would definitely wipe in 3 seconds or so.
All in all, unless some major patches come, changing such core ideas, like repair bots would be too much of a hassle (hence the need for a major patch).
Spios do need some of that firepower given how volks only trade well on long range until the upgrade, but then again, you play ettelbruck or Lienne Forest spawn, you'll definitely get double SPios and will most likely lose that part as any faction (assault sections commander wouldn't lose I think).