That's the way I did it as well class 2 rights then got the class one before issue.
But I would advise you don't do this. But give it 6 months apart from when all your ratings are due. This is purely a cash flow thing. Means you don't have a yearly huge bill all at the same time and issues with medicals requiring to be valid at the same time as getting ratings sorted out.
It can be a bit of a faff trying to get medical, mep and IR all sorted out. Because sods law means that the medical will be after the examiner is available and you need the medical before the examiner can test you.