Actually AH does have supply and attrition.
You can:
- bomb field fuel supplies, thus attriting fuel
- bomb field ordinance supplies, thus attriting rockets/bombs
- bomb field vehicle hangars, thus attriting vehicles
- bomb field fighter hangars, thus attriting fighters
- bomb field bomber hangars, thus attriting bombers
- bomb field barracks, thus attriting troops (used for capture)
- bomb fuel factors, thus slowing down the rebuilding of fuel
- bomb ammo factories, thus slowing down the rebuilding of ordinance
- bomb grunt training facilities, thus slowing down the rebuilding of barracks
- bomb cities, thus slowing down the rebuilding of all of the above
- drop field supplies using C47s, thus speeding up the rebuilding of the above
WW2OL attrition is interesting, however it does have its issues. For example, you never hear the term 'griefer' in AH. Whereas 'griefers' seem to pop up all over WW2OL. For AH guys, an griefer is basically a spy from the other side who simply spawns vehicles and takes them out of the base limits, then despawns, thus attriting and using up vehicles at a base. Then theres the worst kind of griefers, they spawn an Opel and load up with infrantry (ie other players), then drive right into the guns of their mates so they can rack up easy kills (something I could imagine the FDB's being keen on).
The WW2OL attrition system also leads to a lot of 'camping' on both sides. Basically you take a crapload of tanks and park outside the spawn points. Eventually the enemy runs out of tanks, ATGs, infantry, and you can take the town with ease. Allies get the upper hand on this as their takes, albiet slower, tend to have much better armour and get one shot kills easily at close range. So 9 times out of 10 an allied assault is a column of tanks driving to the spawn point.
Having said that CRS have recognised the limitations of the system and are coming up with a new system called Brigade spawning which involves dispersed spawn points and some hierarchal system to help prevent 'griefers' (which I don't really understand but the community seems to have mixed emotions on).
I think AH2 would do well to incorporate attrition on a strategic scale, I'm not convinced yet on using at a tactical scale a la WW2OL.