I would make and eng captain, not a sci captain for it, at least for the fleet Neb. Your weapons power levels will really be hurting even on max attack, and the eng powers can help. Unless they unnerf sci powers, being a sci-sci isn't the best idea, even in PvE.
To be honest power isn't a big deal breaker these days. So many items boost your ship's power that all my ships, regardless of tac, sci or eng, can reach 125/75/75/100 power. Just slot the Borg Console, Romulan console, Plasmonic Leech and a good warp core. Typically, my base power settings are 100/15/15/70 and these consoles will slowly boost them up to 125/75/75/100 when you start attacking. Oh and if you're using beam arrays, add the Nukara Console. And if you can get yourself an elite fleet warp core with the [AMP] effect, having all 4 subsystem power above 75 grants you an additional 14.8% increase in damage.