I don't think you're going to see both Perunovich and Mikkola in the lineup at the same time unless there is an injury. And, while a little off topic, I would like to see a focus next season on complimentary pairings rather than situational pairings in the Top 4. Parayko was paired with JBo and later Scandella as a "shut down pairing" but, as we saw in the playoffs, if they're not 100% on their game, they're not shutting anything down. I'd look to pair Scandella and Faulk because I think Faulk needs to have a stay-at-home guy on his other side and be deployed on the right side for now. I'd also pair Parayko and Pietrangelo, varying which is on the left and the right, giving both the opportunity to pinch and lay back as I think both are flexible enough to be able to play the conservative or aggressive style needed in any given situation. For the most part, I'd be looking get our 2 best D the top minutes and put Scandella an Faulk, presumably the rest of our Top 4, the partner they need to play their best.
The bottom pair will be some combination of Dunn, Gunnar, Bortz and the two new guys in Mikkola and Perunovich, barring any additional trades subtracting from the blueline.