1. What is it you want to do exactly?
Seems like you want to get the last subform, insert it at the first position and then have the subsequent subforms beneath the subform placed on first position...
2. That's it?
3. Can you have more subforms than only 3?
4. Does all the three subforms has the same fields inside them?
5. Or you just want to change the position of the flowed subforms?