Contracts in general are tough to hash out, but in the end, it's usually for the general financial interest of "said" company to protect their assets. My former employer made one prior to myself showing up because guys would come, get a few hundred hours of twin-time, and bounce. While in a C-310 isn't much over-all cost, it does cost them airplane, salary, and check-airman time to cover all the important stuff.

I signed a 2-year contract at my current employer, mainly because I plan on being here that time-frame anyways, but it was for the TBM-850 school. After the first year it pro-rates very aggressively as you can suspect. If there's disagreement, maybe you can draft an individual contract to suit both you and your employers demands also. Not sure if they'd go for that, but worth a shot.