Virtual Gun array settings?

I've been thinking about that for ages — Is it better to use guns with similar attributes & weights but different decay rate, or guns with very different settings?

I was using the former in 0.012m7, then tried some very different weights in main gun in 0.012m8.

What's very interesting is that with main gun only, the performance is increased (comparing 0.012m8.1 with 0.012l29)

But when put into VG array, the better gun results in considerably decreased performance (comparing 0.012m8 with 0.012m7)

What I'm experiencing is that, two strong guns, when combined, resulting worse performance — and the improvement of one of them is making the combination even worse ;)