Builders Hut Shorten Time
I was thinking that a good idea would be that you are able to add more builders to one thing you are upgrading to shorten the time you need to wait...
For example: Let's say your upgrading your x-bow to level 2, that takes 10 days, you add another builder to this and it shortens by half the time, then you can add another builder for 1/3 the time.. And so on and so forth..
Now obviously there should be some sort of pay like 250k gold or maybe 50gems per builder added.
Hopefully this is heavily considered!