My favorite two picks are not on your list.
Cost-effectiveness and synergy.
For example, for 653, I can get an Arrow IV on a Wheeled chassis in the Vali. It also has quite a few bins so I don't need to worry about being only stuck with Homing or Standard, but can mix in Cluster and Inferno if I want.
If I don't have TAG, the Mobile Long Tom is even cheaper (515 BV), and is even more widely available through the eras, and even cheaper, though lighter on Ammo, but what it hits will know it.
The Ballista also works as a cheap Sniper platform that may not be as effective as the MLT, it's lighter and also carries a lot of Ammo for 531 BV.
So, I look at what I am bringing and build to suit so they work together, and its even better if they are cheap enough I can bring 2 or more, cause Artillery misses.