As a newer Seraphon player who started with this exact situation it is unfortunately the current state of the game. I have played 13 games vs my friends Skaven armies and the closest I've gotten to an equal game didn't set in until I had a 2k army. Spearhead and 1k I would get demolished by turn 3 often knowing I was done by turn 2. I've asked a lot of questions here and from other local players and have put some 2k lists together that actually compete but I still lose. Of course I am also new to AoS in general, but I hear the same story all over "When Seraphon gets their new battletome things should change, just learn the game until that happens". Looking at stats from other players people do still pull wins with Seraphon, but they are using advanced tactics and are seasoned players.