Since nobody seems to interpret what I said the way I wanted, I will restate what I said:
Iirc, there was a time when slashers behaved as Xivender wants, I also used fight command with slashers and it worked great. I suspect, since there were no engine changes, that this was due to their smart AI:
They stop when an enemy is in range, and didn't move again until there were no more targets available.
But at some point, slasher smart AI was modified, were slashers would automatically try to kite. This turned out to make them less effective, many assaults and riots could walk into range before the slashers packed their gun, and the slashers would have been better off trying to finish off the unit while it approached.
Result: People started to turn off smart AI.
After a while, people started to notice that slashers now chased their targets, leading to Xivender's rage post.
TLDR:
I think the old smart AI was good, then it was changed to failkiting, people turned off smart ai, which turned out to to have this chasing problem