Long answer. Lots of factors.

Is there fallout if you don't get a particular rating? Like, do you lose your job if you don't get 1st Division?

How do the kids feel about it? Would a new song be an easy sell? Would they jump on board?

If you change, I'd sure go with a super easy grade one. And sell it to the kids as "yeah, this is easy but we only have four weeks and one of those is spring break. With this easy music we can surely tackle higher level musicianship."

That's my short version.