I was in exactly the same situation as you at the weekend, not having played for a while due to Covid and other commitments. I played against FEC and had the same thoughts about my opponent's army. It moves quicker, can run and charge, is better in combat, is better at damage mitigation, is better at healing and getting models back, is able to generate additional command points and has a decent magic phase. Turn 2 or 3 I was thinking "what does my army have?"
My opponent is a very good friend with tonnes of games under his belt from various tournaments and helped me loads in my turns. With his help the game ended up a loss for me, but only by 1 point - even though I essentially only had a wraith and summoned Dryads turn 4 & 5 and he still had 2 terrorghiests amongst other units.
I think the army needs alot of finesse and having had a bit of coaching I can now see that what we have is the ability to score late game objectives. The goal is to keep units alive, not to kill the enemy. Play the scenario at all costs even above kill points. That's what I learned from my game.
Interested to see what other players with more experience than me have to say.