It depends what you mean by a coop. At a local level, you can develop a coop with likeminded neighboring property owners and form a cohesive wildlife management plan. This largely depends on how likeminded your neighbors are. In are case, the cooperation is informal and limited. There is too much difference to develop a cohesive plan. Instead, it is more about understanding what each other is doing and cooperating where a common interest exists. Fore example, we cooperate on trespass sharing information and giving each other a heads-up to catch and prosecute. We have some neighbors who have some harvest restrictions on their lands. That helps to some degree with letting young bucks walk. We have one neighbor who does not allow hunting but will let us trail game on his land. We consider his land our "sanctuary" for management purposes.
We are members of the farming coop in the area. This is more of a business decision. It supports the local economy and gives us reasonable process on fuel and ag supplies.
There are also more regional "coops" like QDMA chapters. This is more of folks with a common interest who get together. This is more information sharing and doing projects together. While there are wildlife management aspects involved, these are usually to sparsely populated for the geographic area they cover to have a direct and significant impact across that area. That doesn't mean they don't have value. They allow for things like borrowing equipment and even labor in some cases, but the biggest affect is information sharing and contacts. We don't belong to any of these. I probably would have joined the local QDMA chapter had they not made the decision to put the organization and message control ahead of the mission when they killed the forum.
Coop has lots of meanings and incarnations and some work better than others.
Thanks,
Jack