Quick question on number of radiators

I'm going to be cooling my 2 Titan X Pascal's soon. I've decided on a 360 and a 240 for the rads. But I was curious to find out if a 360 would be enough to cool them. Also, I don't always have sli enabled so only 1 card is working. It would definitely be better than the stock blower cooler, right?

You should be ok with a single loop for the CPU and 2 GPUs. Yes, it will be better temps than air.