Because it wasn't worth 120pts and died far too easily. I'm still not convinced that it works as it should, it should be able to be used aggressively, not as basically a mobile pillbox, that is how the War Wagon should operate...
are you telling me that the rule change increased its survivability? I beg to differ....
In the rulebook version the tank did NOT have the "destroyed when driven back" part... it was just an ordinary unit. And I find 120 points very appropriate for a mobile cannon (remember it counted as a "great cannon" in the original rules).
cheers,
IIRC, originally the Steamtank unit type was artillery, which automatically gets destroyed if forced to retreat from combat. Either that or it was a machine which counted as artillery. My rulebook is not close to hand, so I cannot be sure on that, but it looks like a throwback from the reclassification of unit type.
As to 120pts being good value for a mobile cannon. Wel for 85pts you can have two cannons, brigade them with something else, and indeed if you shell out 50pts for a hellblaster then that comes to pretty close to the cost of a Steamtank. But more importantly, 110pts gets you a unit of knights which has far more utility in making a big mess of anything you point them at, especially when they've got their mates with them...
Incidentally the Steamtank does well when charged by cavalry, but would suffer quite badly if caught by supported infantry, especially if caught in the flank. Even when up against 6+ armour halberdiers, when charged in the front by two units in line (one supporting the other), 3x S&S+ 3 normal attacks equates to 2-3 hits, and of course the infantry will have 2-3 support (depending on whether the ST does 2 or 3 hits), then three attacks (always counts as defended remember) equates to one hit, which would probably be saved.
Basically any combat involving the steamtank is always going to be very, very marginal, involving very little in the way of dice being rolled with a significant margin for things going either way. And because the steam tank rolls so few dice, actually finishing anything off with it takes many rounds of combat.
Personally I think that rather than having it counted as defended all the time, it makes more sense to make it a 5/3 4 3+ unit that causes terror. It might even make sense to increase it to 6/3 6 3+ that causes terror.
