The point is that it's progress towards finding a better 3rd seamer. If neither of them turn out to be good enough, so be it. Give someone else a go.
I'm over being content with mediocrity. Ideally they'd see it my way and pick Bennett but if that's not going to happen, at least have some type of plan to replace him. He's not good enough and that's been proven over and over again.
You wouldn't be making progress because you're just changing the name from "Wagner" to "Gillespie" next to the poor bowling figures. Gillespie at his best is easily the third best seamer in the country but he has given no indication he is at his best.
I'm well known on this forum for whinging about the culture of mediocrity, but playing Wagner in this test is not a manifestation of it. Wagner has had his ups and downs and his share of good and bad luck, no one denies that. He's taken jammy wickets and the likes of Matt Prior have performed black magic to prevent him from taking a wicket. He has been an inconsistent bowler, but for every Dunedin and Wellington first innings there has been a final day in Auckland, the spell after lunch in Wellington, leading the charge against Bangladesh and that inswinger to KP. He has also shown massive improvement in his technique since his debut. Wagner can bowl at test level, but he has no consistency. Unless he turns it around the lack of consistency will probably see him dropped in time once a domestic bowler hammers down the door, but you cannot drop a guy after his post lunch spell in Wellington and the big effort on this crappy pitch. It's day 1 of the test, what you're suggesting is ridiculous. "Well bowled Wags, but we've decided in one day of the test you've just been picked for you're not good enough. Don't come Monday."
In my books he is on thin ice, but he has shown he can bring the goods and we know his poor spells are not the best he can offer, especially since he was able to pull himself together and bowl well in both tests. McHesson see a bowler who can be a good player if they can improve his consistency. I don't rate their chances because I think he's just too raw and his improvement will take time he and the team don't have, but he still (just) deserves the opportunity to prove me wrong. Persisting with a talented but inconsistent test bowler who has performed to a very high standard in the Shield for a bit longer than you would with a guy who has shown no glimpses of quality at all is not being content with mediocrity - it is backing your selections and trying to get the best out of them. The hallmark of bad sides is lots of players with very few test caps each, because selectors panic and go searching for instant results, and it never works. See England and NZ 1995, NZ 2007 - 2011 etc.
If Wagner is poor in this test match and Bennett proves the early Shield rounds weren't a purple patch of both fitness and form then fair enough, bring him in. I'm not sure I want Henry bowling first change - he's my Southee like for like injury cover - but if he takes a nice haul to get his season record looking like his career record then he deserves to be in the running as well.
Disclaimer: I can't remember if I wanted Wagner dropped after Dunedin or not, but if I did I still back it because he looked shot and needed time out for some remedial work. I never expected him to bowl as well as he did in that Wellington spell, and he proved me wrong.