When I got the Tankspire's proposed stats, I knew there was an issue; now I understand why. Numbers and statistics are critical to good balance, but are not the entire picture: the sum of the parts is not always equal to the whole. Perception is almost as important as the actual stats: look at how many people declare the Minotaur "pointless", while a few have looked past its apparent weakness and found a powerful tool. The way people think about something changes how it is used, which can make a sub-par gun a mainstay, while more powerful ones are not used to their full potential. And the only way to find out how people feel about something, is to ask, or to experience it yourself, and reflect on that experience.
On the other hand, you are trying to change things; too much focus on how it is now can make it harder to see what it could be. Conversely, if you try to change something without knowing how it works, it's easy to accidentally change what makes it work in the first place. Imagine trying to upgrade a computer without knowing how it works. It's easy enough to get the case open, but if you plug something in backwards, it's not going to end well.
Thus, when the proposed changes include altering the gun arcs, we can assume that not enough is known about the current function. As almost anyone who has flown on a spire knows, it's only attraction is the ability to have all three, or even four guns, one of them heavy, on target at once. It's weak health is an incentive to kill the enemy before they can shoot at you. And while this was an experiment to see if changing that fundamental weakness would be practical, that core ability to keep all guns on target is so central to the design that changing it would result in a completely different ship. In this case, a goldfish.
There are fundamental features that define each ship; while they can be changed, extreme care must be taken while doing so. To extend the computer analogy above, these features are not the graphics cards, the RAM, or even the CPU: they are the power supply; the bit that, if you mess with too much, makes every other adjustment pointless. However, once you understand how and why it works, it can be adjusted safely.
There is nothing fundamental wrong with a tank spire. I've personally heard several interesting ideas as to how it could be done. But the proposed changes reveal not only a lack of understanding as to what makes a spire work, it reveals a lack of understanding as to the different ways things can be balanced. Adjusting the turning rate on the spire affects it hugely. Component health, and the tools it rewards, is why popping the balloon on a squid is more valuable than popping a junker. Crew placement and routes are why a mobula armor break is more problematic then a goldfish's, or even a pyra's. Forwards speed is why a galleon is a great teammate for king of the hill, and a regrettable one for crazy king. Each of these factors affects the usage in different ways, and it is important to see what changes one creates before layering on others.
TL;DR:
For changes to be effectively made, you must understand how the item currently works.
This understanding is based not only on stats & numbers, but on perception and use, which can change, and are only measurable via interaction with the system.
