I haven't played the game for 6 years now, but I can for sure make a list of what I know about their weaknesses
Offensive weakness:
lack of anti tank/structure damage output
weak against air unit swarms, ex: carrier hornets, harrier squadrons, kirov parade, rocketeer, etc
heavily relies on mind controlled units to attack
if the mind controlling unit dies, the chaos will turn to your side instead
weak navy
Defensive weaknesses
mind control units & building have a limit to how much they can take on
lack of AoE damage
Doesn't have much to defend with besides units. Since only 2 defensive structures are given
Economical weaknesses
bad transportation, hard to get engineers to distant tech buildings
Slaves are not very reliable when enemies have anti infantry units nearby
Slave miner is stationary for most of the time, easy target for missiles and also hard to run away