Hi, So I 2key CB Nichtmare and trying to get my team better and try UN. I just have a few questions to understand the mechanics better. 

I have speed tuned my team: Geomancer: 178 - FB: 178 - Aox: 178 - Jareg: 246 - Thenasil: 175

I did target 230 Acc and 3400 Def and between 172 and 178 speed and Jareg is fastest 4:3 speed tuned and Thenasil slowest. So Jareg Incr Def and ally prot and thenasil before the stun Incr Def and a heal. 

1. What would more benefit, increase my defense above 3400? Or get more HP? I have always a 60% incr deff up, so my champions with 3400 Deff would have standard 5.440 Def through the fight? 

2. Would it be smarter to have 2.625 Deff, so my Def in the fight would be 4.200 including Incr Def Buff? And have more HP or Crit on my artifacts?