About controlling grouped devices per < group > app:
It has a setting to enter a custom delay time (in ms), which is used between every command to a device in that group.
When you turn the group device on, it fires the commands one after the other very quick, instead of Homey, which fires all at once.
When it’s possible to set that delay to, say, 50ms (just some value), you could control like 10 lights with a max of 0.5s delay between the first & last light.
You can make that delay maybe even shorter, that means experimenting with it until you found the shortest delay, without random lights not responding.
This is also an interesting app, maybe it suits even better:
Light Triggers
