For me T6 took atleast dozen of tries with G7 Juhani. Just RNG and a bit of understanding what you are aiming for (Hit Badstilla when feared if you need to reduce cooldowns etc), I added also potency cross and around ~60% potency for Juhani for extra stun. Helped a lot.
T7 is easy. But I would have liked to play it a few more times, lost by a large margin the first try, didn't fear in the start with BSF. And snowballed the 2nd try and I don't _know_ why, would be nice to understand the battles not just get it done pretty much as auto.