He has demonstrated he will go need if its close or extreme value. Raji was supposedly under Crabtree on the Big Board when Thompson choose him and he went need again in a trade up or Matthews. I am guessing Matthews either had huge value at that spot or was the last of the top OLBs on his Board.
I think the thing we miss with Thompson is that he is not ideological about the rationale for a pick. But he does operate within pretty strict limits.