@Rotor I think what you're seeing is the TM effectively going 'around the clock' from 100% when they hit back up to 50% when it's a critical (+ whatever natural accumulation there is i.e. 2-10%).
@merioonvalhoun GG's gear and abilities are all maxed but he's heavily modded for health with speed and crit chance secondaries. I've tried a crit damage set and an offense set on him and the damage comes out nearer 15K with 10K on each of his AoE hits. The problem I had was that even with the health bonuses from the other droids, he was very brittle. I've been informed by my shard buddies that due to the fear he induces, they always target him first and it's quite easy to bypass his taunt with a solid one-shot that takes him from green to dead. Modding him for health has proven to be more effective because although he does less damage on each shot, he sticks around to make 4 times as many...
Historically I've always run my droids for long-term grinding. This worked really well against the old evasion meta and was much more effective than the usual DPS focus. Recently with the switch to an AoE meta, it's proven less effective so I've had to make changes (benching IG100 broke my heart!). I might revisit making GG into a damage dealer now...