In my last few matches, I've been running Thundertusks because those are the models I have until the Stonehorns make it to the painting table. They've performed much better than my expectations. In both of my last 2 games, my Huskard on TT has been a champ. Those mortal wounds add up, and the +1 to wound prayer has helped the Frostlord push through.
Alvagr Ancient was an all-star. I was running it on my FLoTT, and it helped to compensate for his shortcomings relative to a FLoSH. It created an unsolvable problem for my opponent, who had no shooting and no way to push my monsters off the objective, other than to just push in and give me the advantage.
However, Alvagr Ancient always needs support. It obviously doesn't do much if it's on a HoTT with nothing but fists and tusks to strike first. In my case, I at least had the Frostlord on top and the Brand of the Svard to get some work done before priority came back around. In the ideal case, I'm not running my combat hero on a TT, so I would always need to make sure that I have other hard-hitting assets around to punish opponents for pushing in to my Huskard.