It takes approx. 3 years to build a new team. We are not talking about a short term success here, we should build a new fresh team, and in order to do that we need to get rid of some players. We should build for the future. Long-term. 1 year is not enough.
I know we need to rebuild a team, but the contract length shouldn't determine what needs to be done. Guardiola had 1 year contracts at Barcelona, and didn't stop him rebuilding the team, but he also didn't have Roman above him.
We also need to see how RDM will perform in the league, if we give him a 3 year deal, and we finish outside top 4, then what? We spend more money getting rid of him and getting someone new in. A 1 year deal is just more safe.