Xiaomigateway * 2 = xiaomi battery devices works a lot better on xiaomi gateway)
Raspbee * 1 = deconz have very user friendly scene interface, so much easy to set, scene, event, and a lot faster : now way to know that a xiaomi switch trigger an ikea bulb when using conbee).
Using zigbee since 3 years know, i learn that sperate zigbee network main more stable, more fast answer, more easy for WAF.
So you have 5 zigbee mesh networks? That’s a bit too much in my opinion. The mpre devices in the mesh, the better is the mesh. The only thing that makes sense for me to split zigbee meshes is to have one for ZLL and one for ZHA devices as the communication between these is not the best.
I use a ConBee stick with deCONZ for 3+ years now with 60+ devices mixing Xiaomi, Philips and IKEA devices and I never had any issues with this at all.