The issue is that it makes AI very dumb, hence why it was changed (it was the reason for zombie rush in vanilla for infantry). Plus throw on charge is also a bit bugged tho here AI also gets it worse than player. AI also loves to destroy own friendly units using it.

Anyway, here is the file I made for it, I think should still work with current DeI version, just put it to Rome 2/data folder and load it above DeI in mod manager.

https://www.mediafire.com/file/twp8k7i531we487/%2540%2540%2540%2540%2540precursorcharge.pack/file

Ah damn you Steam, why you wont let me post mediafire links. Use below, just remove space between words "media" and "fire".

www.media fire.com/file/twp8k7i531we487/%2540%2540%2540%2540%2540precursorcharge.pack/file

Thanks! Didn't know it dumbed the AI down, that is indeed a considerable trade-off. Will ponder on that for a bit and then decide if Ill implement it :)

Its because AI does not re-evaluate orders until current one is completed.

Since precursor makes attack order and throw single thing, once AI gives attack order, even from further away, it will rush forward to nearest player unit.
With throwable weapons being treated as separate to attack order, AI first has to tell units to get in range, finish order, give ranged attack order, finish it and only then it picks target for melee attack.

But of course AI is AI, sometimes it might even work ok with precursor so give it a go and see if you like it. The way it works there, its save compatible so you can turn it on/off at any point.