That does not make sense. Currently the risk of abandoning a vehicle is quite low. With recovery the chance of recovering an enemy destroyed vehicle behind your line would be almost certain if one's faction have these tracks available.
Yes, that's what I wrote.
In CoH2, you dive based on the assumption that your vehicle will not be abandoned in case it gets destroyed. In CoH3, your vehicle will be recovered.
Diving a P4 for 2 Katys is absolutely worth it in CoH2 (unless RNG abandon kicks in). Doing the same thing in CoH3 would be roughly an even trade.
These are question that obviously can not be answered here since the require extensive planning the testing.
A rough idea though would be:
Number of vehicles need to be able to build a vehicle would be according to vehicle category (light,medium, heavy, super heavy).
Nope, when it comes to recovery wreck would only count for the specific vehicle or category.
Vehicles would be unlock one by one
answered in point 3
In addition one could use the wreck for other reasons. For example one salvages a dingo armed with bren now one can equip an infatry with bren, one salvages a hmg now can get a free pintle, one salvages one a PzIV, one can give skirt to PzIV or salvaged vehicles can offer discount to techs.
It could be explored in a number of ways, but at some point the mechanic will become to fiddly to be attractive. Do you really want to gather X light vehicles to be able to build one of them? Your opponent could just not build the 3 needed light vehicles that you need. Unit classes are even less defined than in CoH2. How do you deal with that? If you recover a Stuart and a Greyhound, which one are you allowed to build? Which one if the vehicles are even from different factions? What happens if at least one vehicle is from your own faction or the other Allied/Axis? Would it then be possible to exploit that you can build a unit of your Ally?
Is it really worth the micro and resources to build a recovery vehicle, micro it to salvage a wreck and then get a free pintle (or any other smaller bonus) for it? I'd have to do that an insane amount of times to be worth it.
Your suggestion would take a lot of focus from the rest of the game. There's so many questions that will give rise to logical and gameplay problems. Even if you'd achieve a system that is fair and balanced, it would probably not be fun, and that's what playing computer games is all about.
At least the current system is easy to understand and logical. There's a destroyed wreck on the battlefield. You need a specialized vehicle and some resources (spare parts) to get it into working condition again. Or you just scrap it for what you might be able to use and get some resources. That's easy and straight forward, still has some decision making and pre-planning involved and does not need any counters or other indirect mechanics to work. It's an overall better design. Does it fit the gameplay? Is it balanced? We don't know yet, we'll see after release and the first months or patching.
Imo recovery cost and fragility are too few variables to be balance the mechanism across all modes when the price can be something as important as Black prince. Providing more tools would help balancing the mechanism greatly.
To be honest I don't fully remember what the costs of recovery were. But if the recovery cost scaled with the unit's cost, it would already be a decent screw to tune balance. Especially if you don't get refunded if you need to cancel the recovery. You might get a cool vehicle for rather cheap, but pay resources, risk completely losing them, risk the truck itself and have an opportunity cost of not being able to use those resources earlier.