I would be hesitant to give anyone other than a totally elite player anything more than a 2 year contract.
3 years brings out the complacency in people, which is why elections are every 3 years, if they were every 2 years people would be put out enough to get upset about it and make it 3. 3 years seems ages away.
Superstars can be given more than 2 year contracts because they are motivated by more than just security and they back themselves. Gutherson gibbered on a lot about security and being set up by this contract, which should always be a total give away that his form would drop after signing.