So do Handgunners, Crossbows, and Archers fulfill their roles? and what roles are those? I believe that is the question for this thread.
I've looked at the role that the OP wishes to use handgunners for(warmachine protectors) and it might work out, it might not. I'm interested to see the results in his future games.
i think you're right about the direction of the thread, role is more important than "getting their points back"
let me get the ball rolling then, here's how i personally see the roles of the shooters:
-crossbows, useful at thinning down enemy shooters due to their 30" range. will outrange shortbows, bows, handguns.
good at taking down flanking/harassment units (lightly armoured) like eagles due to range and S4 when set up with good fire lanes.
-handguns, useful at thinning down small units of well armoured elites due to S4 and AP, chaos warriors/brett knights etc. these elites will be advancing into combat, so range isnt as much of an issue. these also face competition from outriders, who benefit from vanguard and a 5+save but are not core.
-archers, useful as small detachments for re-directing. useful as a character bunker. useful as warmachine protectors (can move AND fire). useful in larger units for anchoring a flank in woodlands (stubborn in woods)
the roles for handgunners and crossbows are slightly overlapping, but niche enough that there is a distinct choice to be made if you are tailoring your list to a specific opponent.
i do not think they are particularly cost efficient, as a helblaster can put out more shots at a higher strength with AP and can pivot + fire.
as core options, 'gunners and xbows have some merit.
archers have a much more diverse application, a lower price per model and greater tactical flexibility on the field due to skirmishing, possibility of gaining stubborn and the ability to move and fire with free reforms.
the roles are all different, and will work well in certain army builds and against certain enemies.
i would suspect that in an all-comers force, core shooters will be limited to archer redirectors and hbvg's for the tougher stuff.
as for the OP, good luck with the handgunners. it might be worth considering a move + fire option like a hbvg or archers to protect your artillery, as many war machine hunters are fast cavalry/flyers/tunnelers/outflankers and can deploy or move outside of your firing arc.
let us know how you get on!