It would be interesting if custom commanders abilities were auto-tuned by popularity of usage (not just inclusion).This is a brilliant idea and if only someone at Relic would listen it would singlehandedly transform whatever Custom Commanders are into a system unparalleled in the current world of RTS.
Your custom commander has a set # of points to spend on commanders abilities - say 20.
The more popular a commander ability is, the more expensive it becomes to include. If Tiger Ace is really OP and everyone starts using it, it's cost will increase to the point where including it in your commander layout cripples the overall ability of the commander. At the same time, if people stop using something like allied mortar half-track, it becomes a bargain to add it to your custom commander.
I can picture it now :
"Korps supplies overstretched III: +3 points cost to include in loadout, comes 1CP later"
"Abundant equipment: -1 point cost to include in loadout, comes 1CP earlier, ability costs 15% less ammo to use"
This would effectively let the community balance the commander abilities and ensure no ability is ever overpowered (unless Relic has another one of their DEEEERP TIGUR ACE!!11 moments).
The more an ability is overused, the more expensive it will become, until even its OPness will not be enough to justify its inclusion and people will start dropping it from their loadouts, thus stabilizing its cost in a sort of supply / demand market graph.