I think it was this one, but there was also one in Forbes. The whole benefit of the drone as artillery eyes, comes into full view, if one reads up on modern artillery.

Drones do not have to carry the weapons, thus have more room for spare tanks, thus can circle longer.

Artillery has virtual salvos now (if they do not do the full distance combat, which allows them to fire salvos at different arcs, that arrive simultaneously.

I have also read somewhere, that some artillery shells now have "last meters" impact guidance (somewhat similar to guided bombs). I can not find that article though.