It'll probably take a little while...and it really does not help that Megatron is an Angelii and Prime is not. D:

I think what Ratchet is going to do is encourage Prime to go home on regular trips to "finish the fight" on the other side. He feels that Op needs to see how it ends and know that he's capable of not just leading, but leading well. Old bot is a real admirer of Optimus and all that he stands for...he really wants to see the guy succeed.