On the topic of lower level players struggling: this happened to me. I came in when Kraken/Troll/Mab/whatever was the meta. I was at level 200 something, unsure of exactly what the hell I was supposed to do against a team I couldn’t possibly out play due to the stat difference.
The problem isn’t what the end game meta is, the problem is the matchmaking. Address that, and Doomskulls/Kraken/Ish/Infernus disappear. Very few people will have an end game meta team ready to go at level 200+.
On the topic of Doomskull defenses: I have lost to one out of the 20 or so I’ve managed to find (on purpose) in PVP. If worse comes to worse and I find myself losing more, any “take reduced damage from skulls” goes up first. Pretty simple fix. (At my level, again, see above for beginner players).
Everything else: I stopped using the Doomskull teams. I found them more annoying than fun. Critical thinking and observing the board is for Bejeweled and Puzzle Quest, both of which I play from time to time. Gems of War is about exploding, killing, dying, etc etc. My Divine team can’t wipe out 4 troops with one cast, but it can nag away for about 15-35 seconds.
My Doomskull team can’t nag away, but it certainly, on average, for me takes longer than 35 seconds to put together a 2 second Doomstorm that after seeing about 30 times, is old.
Final thoughts: Doomskull troops are a novelty. At first they are amazing, but now, they are just another “raid/invasion flavor of the week troop”. For lower levels, they are great. I’m end game, so to me they are meh. They aren’t fast, they are barely efficient, and I’d rather donate for legendary tasks to my guild every so often during play than browse for random cascades, then hope to get lucky, then possibly donate.
The only thing broken about them is… nothing. Matchmaking is at fault. And I’m sure I, and somebody else will occasionally get caught by a Doomspam and lose a match. Hell, I have fully traited Divines, max level, and I lost to a firebomb team once. That was before doomskulls came out. I was laughing my ass off.
On average though, anti Doomspam teams are already working, and after a week or two this will become another feature in the game people are used to, rather than the focal point.