Good point. What Thomas has gone through before being put in Stasis is likely many times worse than what Shaggy did to him. Plus, he doesn't have the real Justine anymore (or perhaps his illusion of her is gone).
Question: Is a hypothetically well-fed Thomas actually a match for Lara? I actually don't think so. I suspect that Lara, Thomas and Lord Raith are the three strongest of the Whites, but that doesn't mean that he can take down Lara. She has too much experience, is older (and therefore stronger) and probably knows how to use the Hunger to achieve a wider range of tactical objectives.
Add to that, Lara has had the time to peruse her father's library; which I believe was supposed to contain a great deal of magical knowledge. My guess is that probably meant White Court vampire abilities. Way back in Blood Rites, we were given a description of Lord Raith's 'kiss of death' technique, which he would use; presumably against other White Court vampires, to start business meetings of the Court to get everyone's attention. Harry even teased Lord Raith about his inability to use the kiss of death any longer because of Margaret's death curse.
I'm think this is an example of Chekov's gun. We've been given a graphic description of a rare and powerful White Court vampire attack method but we haven't seen it used; at least not yet. My hypothesis is that at some point we will get to see it used. I think it could occur in the next book.
Most likely, that means a resurgent Lord Raith uses the kiss of death to show everyone he is back, or; and I think this next scenario is far more likely, Lara Raith uses the same ability to show those in the White Court she no longer needs her father as a figurehead to maintain her leadership of the Court.
I suppose a third possibility is that Thomas will get the opportunity to learn this nasty trick and his father's other secrets, which will allow him to challenge Lara and become the leader of the White Court, but at present that seems highly unlikely to occur.