I think range is not the deciding factor when looking for an artillery piece. i do agree that M-110 is an old system however I wanted to read you views so I kept asking you to elaborate as you always have interesting views to share. The utility of M-110 is still there in my view depending how effectively an old system is used by exploiting enemy through M-110 strengths.Range means more mobility options, even if the armor is moving towards the enemy, the further back the artillery is, the safer it is, the more terrain it can use and the farther it can retreat in case needed.
Let’s put it like this, the armored forces have pushed into enemy territory and you have two types of artillery pieces, one has a shorter range and hence you need to put it some 25KM behind your forces so they can engage effectively, another with a 50KM range can be stationed further back. Both have the same mobility. Now what if the terrain 50km behind the frontline is safer, has better ground, has better cover/concealment, is closer to your supply and communication lines. Has better AD coverage and less chance of enemy counter fire etc. in that case range definitely does matter, even when advancing with an armored column and using shoot and scoot tactics. It matters even more so in defensive situations.