rush to TH9 asap. I rushed to th9 with th7 defenses but max offense bk10 and max lvl8 walls and had no problems.
Now after 5.5 months i have lvl30 king and lvl22 queen upgrading to lvl23. I will be a fully max th9 with 30/30 heroes and full lava in 7 weeks and 2 days from now with 5 builders working all time.
no point staying in th8 with full de storage. every single day you stay in th8 you lose your queen upgrade.
This game is completely unbalance. TH9 have 50 lvls of heroes combined even more than TH10.