It might be possible to complete it in 11 days, but where do you get the gold to buy the required number of heroes? For me, the main bottleneck was the lack of gold.
Added 2 minutes later
I once arrived on day 15, and he didn't have a full tower!
Definitely replay! :)
Build a fort + shipyard + ship in the village = 8000 gold + 50 wood.
