Today at Cloud Commerce Pro we have released a new order allocation screen that is clearer and has colour coding to show where stock is available (or not).
You can still select no orders in your queue and choose the allocation option from the actions menu and CCP will work out which orders can be allocated from current stock. Further you can target allocations by ticking the orders you wish to be considered for allocation.
With this new release you can also bulk unallocate orders using the same action menu. Follow the above procedure but choose the unallocate option.