I *think* the differentiation is there because the suits are different thus the powers are different., but I didn't create them so can't be sure.
The Vindicator II entry refers to the Geothermal suit specifically in the powers section.
The History section of the the Guardian II entry is pretty brief and links to the Vindicator II section for more details.

I'm all for merging them, but I don't have the time to do it personally.

If you want to create one standard entry for Mac and one for Heather, go for it.