You sure can - that's the entire premise of SLI/Crossfire, but for this trick you will be using them as separate cards instead of aggregating them into one unit. In fact it doesn't even need to be the same card - you can just pick off a cheap RX570 and use that (in fact, pick up an RX570 8GB and use that as your main screen GPU, it's more powerful than a 1050Ti). Some people run their second monitor off the CPU's iGPU, though first gen Ryzen doesn't have one.

This is of course assuming that you want to display different application in each screen - having a single screen split to six monitors would probably not work with this, but don't quote me on that.