Upgrade to th 10? or get lvl 9 walls?

I would do full legos and at the bare minimum... heros at 15 each.

Im full legos with 10 lavas. Lvl 15 heroes. Staying th9 until lvl 30 heros full lavas. Look at it this way, would you rather be a super strong th9 or a weak th10. A strong th9 will have easy time in wars attacking th9s. If you go th10 you will be the weakest th10.