Hello again. 
I can’t find any reference to Schneider Electric or Wiser or FESH in the docs, so presumably there are no integrations for these and you won’t be able to use them with Home Assistant. I may have missed something, but the list is here is you want to have a look:
If they are Zigbee gateways, what you should be able to do is remove all the devices from them and pair those devices with your Sonoff controller using Z2M. The Schneider Electric, Wiser and FESH gateways would no longer be needed. Even better, get rid of the IKEA gateway too and put all your devices in one big network.
This will give you a much stronger network than spreading the devices between five gateways. By the sound of it you will need it in a 5-storey house.
As I said in response to your other post, a Zigbee network can only have one coordinator,
Lots of useful information here: