Dear authors of armylist upgrades,
when you wrote "Instead of being deployed separately, bolt shooters may be attached to a unit of legionaries." you meant:
a) deployment in an army roster, or
b) deployment before battle (after outscouting in PBS)?

If a) then the armylist should containt the option of upgrading a legion with a bolt, together with points;
if b) then the example given in the armylist Notes is illegal, as you cannot field a 5-base legion, so the bolt would be added to the unit during PBS as the sixth base.

You do it when you create your army rosta. The bit in the Special Rule that says "Add "Experienced-Light Artillery" shooting to the normal characteristics of one base of a legionary TuG" tells you how to do this.

Thank you sir, I expected this but wanted to be 100% sure.

Still no points in armylist for that upgrade.