I think that opinion is countered by the amount of lists that would use a Thunderquake with a jade battlemage. The bastiladon will probably not kill a lot of units, but it eill definitely hold its ground. Combined with the healing, and a jade battlemage this makes them stupidly hard to kill. Now you have board control because an opponent who knows bastiladons will avoid picking a gight with them because they know it is a waste of their points, or they will send their best unit at it in hopes that the dice are rolling their way. You may choose swift for the first few turns so that shooting is improved. Throw in a starpriest and most of your shooting from the Steg or Bastiladon becomes 2+ or 3+ rerollable to hit. Later when combat strikes up you may go savage and reroll saves. If I was playing a hold the objective I would probably put double bastiladons and sit, one with a slann and engine, and the other with a jade battlemage and a skink starpriest. The choice of salamanders, razordons, or kroxigor is up to you, when I was playing skaven I would take krox, just for the moon hammers. When I was playing stormcast I took the salamanders, an when I was playing dwarfs or Fyre slayers I would bring the razors. The dwarfs are a slow army, so I can force the charge, especially if I am holding an objective with a bastiladon. Stormcast has some great deep strikers, so I use the salamanders as a deterent. Skaven or undead are cheap and come in numbers, so I like to take out as many as possible with kroxigor holding them up for a turn or two. Choosing to go swift or savage will change how he plays as well. If he knows I am rerolling saves he will probably not waste time on a shoelded in cover bastiladon. In short Thunderquake gives good board control.