Recently I've seen a flux of small point value lists (I consider 1500 small for reference) and I've been taking particular note in how some people like to run/equip their various units. For example, a common build I've been seeing a lot recently for tactical marines is a missile launcher and a flamer. Delving deeper, the common reason is "well, it can shoot a tank and toast a horde of orks!" And this build pattern repeats itself in the army where they'll have 3-4 squads each with an anti-infantry and an anti-tank weapon. As a matter of fact, I think the Assault on Black Reach marines come built like that. But, is it the right move?
I can understand wanting to have that old boy scouts motto of being prepared be applicable to everything you have, but shouldn't that be something you have applied to your army in general? Not the individual units? I'm a big fan of specialization, and I will admit that the habit does stem from playing a specialist army (Eldar), but that doesn't mean to say that the same mistakes can't be made. For example, the community recognizes Dire Avengers as being one of the best shooty infantry units in the game, but the Exarch has melee build options. Why? Well, first off, it's a hold over from 3rd and 4th, back when mech was something noobs did. Second, I think a lot of people perceive putting a power weapon in the hands of one model makes it a viable assault unit. In reality, I'm just going to laugh off any Eldar assault lead by a power weapon toting exarch. S3 + T3 + power weapon x= assault unit. Or even a unit that is capable of handling whatever situation is thrown at it. Honestly, I almost feel like the Dire Avengers having any assault options is a misleading joke that GW just throws in there, and I don't understand why people fall for it. As I always say, to succeed with the Eldar, use their units for what they're designed to do.
If you can find a double use for a single build though, well, now you're thinking ~_^. For example, Fire Dragons are excellent tank hunters, but their S8 AP1 weapons also happen to be good at roasting Tyranid monstrous creatures, and War Walkers with a scatter laser build not only make hordes run in fear, but 24 S6 shots outflanking makes almost any tank quiver in its treads. Dual purpose builds rock and should always be taken advantage of.
Anywho, back to marines. So let's say Jimmy wants to run four tactical squads, and wants to make sure he has good tank hunting and a horde contingency available. He decides to go the way of the Salamander and use meltaguns and flamers, but how should he equip the units? Following an emerging trend, he would put one multi-melta and one flamer in each squad. But here's the rub for me. Jimmy may think he's covered, but what if he was a monstrous creature and a horde of gaunts in front of him? A flamer is worthless versus an MC and the squad of gaunts will just laugh off a single melta shot. And here's the kicker, let's say it's critical that he needs to take down the MC. Jimmy may end up firing all four squads at the MC just to get the melta shots in, and everything else, from bolter shots to flamers just go to waste, and now the guant squad can swarm him. How do you remedy this? By combining your special weapons together.
Plague marines are fantastic at this. I dedicate each squad to either flamers or melta guns, and then on top of that, I'll give each champion a combi-weapon to match. So, if I were to use the same scenario, I can bury 6 melta shots in to the MC and 6 flamers in to the gaunts, which is much more efficient.