Thor is a little more interesting than that. First, the home/road splits are all small sample size. Anaheim is not a hugely unfair park. Thor has also been very good in his last 4 or 5 starts.
This is a different Thor. Velocity used to be more 97-98 and this year is only 94-95. It was 93 last year so some improvement. Thor has also never had a big strikeout rate. Career 9.5/9 is good. This year he is clearly learning to pitch more. His control is still pretty good (2.5 BB/9) even with the lower K rate (7.2/9).
I don't think Thor is great. Is he better than Bailey Falter? Probably. Will he cost much? Decidedly no because of his salary. I think a non-top 30 prospect gets him and even then the Angels would pick up some of his salary. Bottom line is that there are worse options out there. If we do not go for a starter with controllable years I'd be OK with Thor as a 5th starter depth move.