I would say that's a function of their current situations. If Phillips were leading the B1G I imagine he would say something entirely different right now. The fact of the matter is the ACC is basically stuck in their current circumstances based on grant-of-rights and TV deals signed by his predecessor so he can't do anything about it. As a result, his best option is to talk about preserving the status quo, maintaining stability, and traditional college / student-athlete values. While taking very subtle shots at other conferences for making it a "zero sum game". If he were leading the B1G he would have the flexibility to pursue expansion, and be in a desired conference that many would want to join. As a result his stance would be very different.
I wouldn't confuse what he is forced to say to defend his league's current circumstance with what he would do and say if he were in an almost polar opposite circumstance as B1G commissioner rather than ACC. I usually like Stew Mandel but it's a pretty silly comparison in this case IMO. Like beyond being an overly reductive comparison, its highly misleading.
I still would have preferred to have Jim Phillips over Kevin Warren, but Warren's handling of the USC / UCLA move (whether or not they reached out to him first, which I've seen some folks use as an excuse to continue slamming KW and discount his part in it, attributing it instead to Gene Smith of OSU) and the follow-on from that (now being patient and letting things (ie ND) come to him) has been impressive and has improved his stature in my eyes. The handling of the Covid thing was still a total disaster, but acquiring USC UCLA and negotiating this next TV deal matters a lot more for the long-term future of the conference than bungling how to handle one wacky partial football season in the midst of a global pandemic. So if he gets this "right" (realizing it's never a binary yes or no) I would say this clearly outweighs what he did in 2020 when he was first getting settled into his seat.