These are the recently updated sets? The Weather Trapper set I already knew that was recently added and did not needed a update, but reading the current analysis again, it appears that the other mentioned sets weren't updated.
Weather Trapper - Uploaded Aug 16, 2012
Substitute - Uploaded May 15, 2012
Magma Storm - Uploaded Mar 19, 2012
Sunny Day - Uploaded Jan 15, 2012
Scarf - Uploaded Jan 1, 2012
So Weather Trapper is the only set that was written post-BW2 era. It may be true that the original set entries are well-written and requires little rendering, so that may be what PK Gaming is trying to get at.
I do believe that we have way too many Heatran sets with Magma Storm, though. Keep Tobes's Weather Trapper and remove Sunny Day (which is essentially Tobes's set) and Magma Storm (which is quite outdated now and serves similar purpose as Tobes's set). Their removal would make Heatran's analysis less cluttered.