[skellyo]

Actually, with the cells in parallel, each set (1 cell from each pack) of paralleled cells will try and stabilize at a voltage that equalizes them. Essentially, the balancer then will balance each set of paralleled cells as a single cell since the voltage will be equal in the cells.

However, while it should work fine, it would really be easier to just use 2 balancers and parallel the charging input into the balancers instead.