First ring with PWL 1000 and second ring with PWL 500 wifi

good morning to all

I currently have a netgear PLW1000 wifi powerline.
I would like to add a new powerline ( still on the same powerline and same router) but older Netgear poweline 500 wifi
I have read that it is possible to create two powerline networks on the same electrical network.
My question is about performance.
The first powerline network has the features of the PLW1000, the second network I will create with the Powerline 500 will be slower.
Being on the same powerline network but with separate powerline rings, will the two networks affect each other in terms of maximum speed?

I have read that if you add a slower speed adapter on a higher speed powerline ring the whole network will adjust to the slower speed.
In my case (two separate powerline rings) this should not happen, right?

Thank you very much
Regards
Ezio Audano