How about from now on, we test 1-2 things, really, really, REALLY well, over a few weeks then put it in. Do that all the time, just one or two things, rather 6 months and 12 things.
This.
Testing one or two things at the time would also make it a lot easier to give and review feedback once the change(s) is added to the game, and gamebreakers like the current (unless you fixed it by now) lochnagar could be avoided. I'm sure some changes would lead to necessary compensations in other areas, but even then the changes should start small and later be adjusted/corrected if needed. Especially when it comes to something being implemented in the game. Nobody likes change.
I also don't see the need to be so radical with the changes. For example, why not just start by allowing loch to fire two or three shots before it breaks to begin with? Didn't work? Ok, let's try to give it two more shots and see if that's better, or maybe changing the damage output or something else to achieve the wanted results.
I have no idea if this would take up more of your time, but pushing a lot of changes regarding different areas could easily result in unwanted results due to changes not being properly tested *together* before making it to the game. The pyra nerf is a good example (although on a smaller scale since it didn't affect anything other than the pyra).