If you don't care about the shot index - and expect golfers on your course not too give too much about it - let it be.
Index is quite important for golfers playing with different handicaps - it tells them who gets a shot on which hole. If you want a realistic index, you need to sort it by difficulty, low numbers are hard, high ones are easy, and to assign odd index numbers to the front 9, even ones to the back 9. Or vice-versa, I forget.
You will find, should you want to change, that you've painted yourself into a corner because all the indexes are already assigned to their holes and are now blocked. In that case the best way would be to delete all the tees (Debug ON, search field: "Tee", select all and delete, Debug OFF), then quickly replant them with your new index values sequenced correctly.