How kepware handles failure of 1 device? - is it better to have 20 channels with 1 device inside?

hi 

I am using kepware to retrieve information from 20 mitsubishi plcs fx3u on ethernet channel.

At the moment i have only 1 channel and 20 devices configured inside but i am wondering if this is the best approach if 1 of the PLCs fails and it might choke whole channel communication.

Would it not be better to use 20 identical channels with only 1 devices in each? what would be the pros and cons of either solution? Which would be better solution from robustness point of view.

Best Regards