Not all victron devices have the same type of remote ON/OFF. For example the Multiplus inverter Aux inputs use 5V logic while other devices used battery voltage level as the ones you show.
Not sure if you can parallel the Orion and phoenix smart directly but what you can do in this case is connect EXT IO4+ to battery positive terminal through a 1kOhm resistor and then connect the EXT IO4- to H connection on the two devices and that will sure work.
Since the Battery Protect is just one device you can just connect it directly to EXT IO3 just need to take care of polarity with EXT IO3+ connected to L and EXT IO3- connected to H
Not sure which is H and which one is L on the BP220 as they have no real standard but to find out you just use a multimeter and see which one is positive and that will be the L (I know it seems confusing but L is pulled high with a pull up resistor internally and can be used as a remote by connecting that to GND) on the H is zero volt but if you connect there battery+ you can turn ON the BP220 so either L or H can be used as remote or both if you short them as the L will be pulled down by the H that will be supplied by the L :) So they sense both on L and H.