Considering the amount of damaged assets most people repair during the combat, like the static AT/AA guns, vehicles... Well that's all of them in a nut shell. It would make tad bit more sense to have a welder for those repair purposes then a wrench...
Probably while repairing or welding that bofor / vierling back into one piece, naturally that welding mask needs to be on that face, so it limits one's field of view to very narrow area and might even prevent combat repairs at the vicinity of main battle. So kinda like simulates that damaged tank retreats to the nearest repair depot / base for repairs and probably for the crew a replacement tank.
Sure at this moment for the next patch not possible to get but perhaps at later point of the mod?
Yeah, though up this idea partly from CoH and that other thread about anti-tank grenades when (was it mudra) that mentioned "I just imagined of a soldier running up to a tank with a plasma torch".
I'd probably try to mod such thing myself but since I don't have any kind of experience to 3d modeling...