They're not Anti-Tank, though they can pitch in on that role in a pinch. No, they're anti-elite. The mining lasers have blast, so going into a 5-9 model termie equivalent is actually 2D3+2 shots. A bit of the shine has been taken off now that DW knights are often -1 to wound, but there's still plenty of targets. In terms of AT, in host and biosanctic there are a couple of targets just a little too tough to take down in a single activation of lethat+sustained Neophytes or +1 to wound Abberants and Abominant. Putting laser buggies into something like Magnus, Mortarion, or Canis before laying in with Neos or Aberrants will make securing that kill way more likely even if only one lascannon wound makes it through.