I don't have any empirical evidence, but I don't remember us blowing a big lead after one of McCaffery's line changes. They seem to be able to at least hold their own until the starters return.
The second team doesn't have the offensive firepower of the first team but they ha e been as good or better on the defensive end.
I didn't rewatch to confirm, but I think at one point we had our defensive lineup in and actually increased the lead by 4 against Minnesota in a several minute stretch. Not that it was because they scored a lot, but because they got stop after stop and did get a few run outs and free throws.