Tree of Perdition & Illusionist's Bracers

[[Tree Of Perdition]] and [[Illusionist's Bracers]]

Obviously if I equip the tree with the bracers I can copy its ability but how exactly would multiple life total exchanges work on the stack?

Assuming everyone is still at 40 life total would it exchange one 40 for 13 and then the next 40 for 40? Or would they resolve together forcing you to choose the life total of two?

Thanks in advance!