I made the farming enjoyable i hope. we plant the vegetables, waiting while they grow, or maybe not? Of course not! we have to obtain them and deliver it to the trader to get coins. While we do this, the vegetables are growing.  
The earth ponies can run with the load while pegasi cant run and cant fly, unicorns cant run. So earth ponies are better to farm.  
I plan chariots too but i have to design how that looks in 2d. Im thinking on that they cant move up and down straight. Maybe that looks the better.