@muzza At the beginning survivors would have the option to lay down 8 units (7 normal, 1 borrow) like normal. Infected have 8 units as well. In the first wave you are incorrect, an infected player would have the option to lay all 8 down or not. The restriction here would just be one spawn point during the first wave. If the infected player had more than one it gives them too much leverage, as it is now.
As far as using units at 40+ its all apart of how you wish to build your team. If you choose units that have longer respawn times, then you must account for that.
The situation I describe doesn't over powers the survivors because either player doesn't have to lay down units all units at once. It also helps the infected to a certain degree, by having less units to defeat up front. The infected still have a slight edge due to the mobility of laying down units anywhere on the map.
As for a survivor laying down a timber beast in the middle of ranged units, well that is all part of the game. The infected will have a new challenge and have to think on their feet. All in all though, the infected have a horde that is mobile and can drop units at very last minute such as a Doomsday or Harbinger and inflict results similar to the survivors. Just remember you have two live players actively changing the course of a battle. One possible perk to give the infected would be a larger than normal base of drones.
I think live play would make it very interesting for both sides and make it more of a challenge. The infected have too many advantages currently throughout the game PVP included. I think this would allow for more real time strategy and better team compositions. The whole point of this is to try and make something that is more aligned to the middle. At the end of the day, I feel like players with teams like @Machiavelli should not be beaten by low level players with mediocre teams.
@Rick I'm suggesting ideas, not complaining. Please don't troll a thread devoted to ideas.