Good Roman ranged units?

[Thoros of Myr]

I've found Velites to be OK. I worked hard getting some up to 3rd and 4th XP lvl and they really dice up light inf. and if you use them right it's not hard to get off 3/4 or all thier shots. They are decent on castle walls too. All in all they are OK if you get them some XP but you never need more then 2-3 in any army becuase after they throw all thier ammo they are pretty useless.

The stardard roman archer is decent. Again I progressed some to 3-4th XP lvl and they became quite useful in many situations but not powerful really unless on a castle wall.

Onagers are really good for breaking into a fort/city, you don't have to wait an extra turn to assault and they can destroy 2 towers, the gate and two walls in the time it takes a ram to destroy the gate and a wall. Thier range is also quite far. I havent to try this yet but I imagine 3+ onager units (6 launchers) fired into the town square would be devastating to the defenders and with the AI always sitting there you could take thier general out easy. Using them on the open field is not so good unless you are the defender. One onager by itself is not very accurate but when start adding 2 or 3 they do hit often.

Scorpions and ballista are fun but it's questionable how many kills they bring, I would only consider them for seige defence and maybe assualt if you devise some strategy, but seldom use for open field. They arent too accurate.

I had some aux cav trained but didnt get a chance to use them before I won the short campaign and I'm sick of rome factions now :)

[metatron]

It depends on the armor of your opponent. The gauls will fall with an arrow barrage, a Post Marian First Cohort won't even flinch.