The legion veteran tactical squad is an elites option for the 30k space marine army. It blends aspects of the 40k sternguard, (or even chaos space marine chosen) with a whole slew of options available to it.
What sets these guys apart from their brothers is their vast experience. They have a rule called "Veteran tactics" to represent this. In brief, this allows the fielding player to select from fearless, sniper, furious charge, outflank and tank hunters prior to beginning the game. More than anything, this is the singular rule that sets aside these squads from the more regular tactical squads. That, and an extra base attack.
I personally can see a multitude of roles for these guys. So, fundamentally, its up to the controlling player to determine the purpose of these squads in advance and build them accordingly. The real challenge is not to sink too many points in to these squads (in my opinion) and to not waste a valuable elites slot which is dominated by a plethora of very viable and exciting choices (which I already started reviewing with the legion destroyer squads).
Here are some sample builds to whet your appetite.
Legion veteran tactical squad, 10 members, 2 missile launchers with suspensor webs, upgraded with flakk missiles, legion vexilla (270 points)
This is a tank hunters special rule squad. Sit at the back field and shoot at will. Move up (thanks to the suspensor webs) and carry on shooting as you go. Use the other marines to sacrifice in favour of the missile launchers. Take out fliers with the flakk. The legion vexilla provides a re-roll for morale tests, just in case.
Legion veteran tactical squad with 5 members, all with melta-bombs, all with power weapons, rhino (235 points)
A squad that rides up to an enemy tank, applies some melta charges and chews up any transported enemies with their power weapons. Nasty - but its a bit pricey. Terminators probably do this better, especially if equipped with combi-melta guns. Probably give the furious charge rule to these guys?
Legion veteran tactical squad with 10 members, 2 heavy bolters with suspensor webs, sergeant with a power fist, 3 other veterans with power weapons (285 points).
Give this squad fearless. Then go hunting for enemy infantry. This squad is nicely suited to countering enemy assault squads or devastator like squads. The fearless makes them great at moving around the board unhindered. But remember: they still die like every other space marine on failing a 3+ save, so be careful about their placement and deployment!
Legion veteran tactical squad with 10 members, 2 plasma guns, sergeant with combi-plasma and power fist, all with melta bombs (280 points)
Give this unit outflank (or even sniper, to be honest) and set them up to cause a little bit of back line havoc to the enemy. Add a rhino, legion vexilla, and/or nuncio vox (especially if deep striking) to taste.
Legion veteran tactical squad with 9 members, 2 melta guns, sergeant with power fist, rhino (265 points)
This might be an entertaining option to place a legion HQ choice alongside with if the Legion command squad is not doing anything for you. Hop in the rhino and drive around doing general damage and mayhem wherever is required. Take sniper for fun with the melta guns perhaps…?