Dual mec Pyra is a very good build, I have used it many times. 
a five gat Junker is a very unusual build with incen rounds, it would be a great disabler/ amour stipper. 
I did think that the dual merc had served us rather well for it to be that dumb a build. It works well for us because our gungineers are reliable as hell for landing their shots. I call a component to disable and in the next shot it will be down. Charging hwacha fishes are probably the most entertaining thing to deny, especially when you wait out that rebuild before hitting it again.
Honestly, double merc pyra makes me feel like the biggest douche in the game, and I love it, even if flying it largely consists of "press a a little, press d to straighten out, move backwards to avoid sand cloud"
Those two builds are actually legit for situations, for example along side a heavy flak spire or a flak fish, all gat Junkers are not rare in public matches, as long as the ally has explosive damage.
Double merc pyra, I've seen use on a swival pyra in competitive, very efficient
Well, I think I will be sticking to pubs for quite a while, maybe til we hit our early twenties. Our clan is small and unfortunately, only four of us are regulars right now. I'll try not to get too attached to loadouts that only work in pubs, though, for the sake of a potential future.
I prefer support/disabling/stripping ships to kill ships, but the all gat/flamer junker is only something I go for if I see an exceedingly low-level crew rolling out in one of the harder ships for pure bullying purposes. It's a real giggle.
