With all of that said about what I think they'll do when Guentzel is back, I'd like to keep O'Connor-Eller-Nieto together to see if they can continue to click like they have today. It's not just O'Connor and Eller, I think Nieto has been really good tonight as well. I don't expect that to last but running with that kind of hot hand line is the kind of line juggling Sullivan should do.
That line playing well and sticking together makes the rest of the lineup fall together really easily: Zohorna as the 4th line LW and Smith-Malkin-Rakell as L2. You're going to need to do something to address the 3rd line RW spot, because Nieto isn't a long term solution there, but running with the hot hand is totally fine.