This really isn't so much an anti-dragon base. Typically for those bases, you'll see more centralized air defences. I've been attacked many times in M3-M1 with maxed dragons and they frequently take 50% of the base including the core. It's just something to expect vs dragons. The other way to deal with them is to push out your outer buildings so that an inexperienced attacker will have the dragons circle the base while being hit by the defences.
Personally, I would rather protect vs what my expected attackers in the trophy range I'm in would generally use (what would account for 90% of the raids vs me) rather than worry about the 10% of the outliers. I don't think any base design is safe for all types of attacks.

