Why not just one using Balanced mode and let cgminer balance the work between the three pools?
What params do you use for the three different instances? (and -ICA:5 does what? Limit number of icarus devices to 5? So -ICA:* would grab all of them?) Do you know if this is working with Anker 10 port USB 3.0 hubs? It wouldn't in cgminer 3.2.1
Balance doesn't balance well enough to compare pools objectively.
With 15 Erupters I would use "--usb ICA:5" for each of 3 instances for a total of 15 devices. That tells CGMiner to use only 5 Icarus devices per instance. I don't have to worry about which five or what com port they are mapped to, just uses any available five.
If you want CGMiner to grab all Icarus devices then use NO parameters besides your pool info.
Quality control seems to be good enough with the Erupters that you can actually compare apples to apples to see how well a pool is doing. For instance I can see objectively how much better stratum is than getwork.
I have no idea about Anker USB 3.0 Hubs. I heard all the trouble others were having with those so I chose to skip that problem altogether and get a USB Hub that would not cause problems. I guess I'm just odd that way.
Sam