No argument there (though you did leave out 24 year old Markstrom who would go on to come in 2nd place in Vezina votes the season after he left the Canucks (yeah, he's flamed out but that was several years later & it's not like it was from a recurring injury he suffered as a Canuck). Plus, significantly different priorites as Gillis for most of his time was hired to take the Canucks to the next level. That wasn't Benning's job for much of his time here (I'll give him a 'mulligan' when the Sedins were still under contract & it's not like those two were that huge an anchor as they were largely responsible for one of the two times the Canucks made the post-season under Benning's watch).
Look at the state of the farm club when Alvin/JR came aboard. As empty as it was under Gillis. No excuse there (imho). Blueline a complete mess outside of generational talent Hughes (who somehow was able to develop under AHL coaching that Benning was responsible for). Myers wasn't a flop but he's in exact same state as Bieksa was (imho) when Benning came aboard. I don't think bad groan Garrison is mentioned much (in a negative light) because he fetched us a 2nd round pick without taking any garbage back. Either that's a testament to Benning's abilities to trade a bad asset for a real asset or maybe he actually had that value (in spite of the NTC). Garrison played top 4 minutes for the Bolts before that groan gave out (ouch, that hurts me even to say that.
Both GM's ultimately failed (for different reasons as each had different objectives).
Pat Quinn is still the benchmark to beat in rebuilding a club. And it's not even close. IMHO.