This. Admittedly I've been a bit less lucky with my streaks (and attacking before changing my team back in the morning doesn't help either :P), but if you can field a full team off same type SRs you should have no problem against lv1s. Just make sure you have good help backing you up. Don't forget that even if your opponent has an SR slayer, it's pretty useless because the multiplier isn't big enough to overturn type advantages. Only the usual whales with multiple slayers are an issue so just avoid the people you tend to see high on the event rankings.