Well, let's do a simple thought experiment here.
If you were to take this SoR+Wyrm deck into PvP, in order to pull off the combo in one turn (i.e. deal 100 damage in a manner that made the opponent's active control cards useless), you'd need:
2 Wryms dealing 80 damage (i.e. 1 Wyrm, 1 PU, and 4 Shards of Readiness)
3 Wyrms dealing 40 damage (i.e. 1 Wyrm, 2 PU, and 3 Shards of Readiness), or
5 Wyrms dealing 20 damage (i.e. 1 Wyrm, 4 PU, and 2 Shards of Readiness)
I just put together a hypergeometric distribution in Excel that shows the likelihood of drawing one of those combos being over 50% (i.e. "likely") starting in turn 6.
That's a freaking fast deck. And because it's a "surprise attack" deck, it's hard to stop.
Is it overpowered? I honestly don't know, what's the typical kill speed for an all-upgraded rush deck these days? If it's less than 6 turns, I'm not worried. If it's 6 turns or more, then we need to consider nerfing Dive or SoR. I still think it should be Dive.