You seem to make a distinction between his positions and his character, but I see none.
His stated positions are meaningless, the only thing with meaning is what he actually does.
So far his deeds show me that he doesn't have enough philosophical motivation to join up and fight in a war. A war somewhat similar to the wars he is now supporting with other peoples' lives. So it makes me question his real motivation for supporting these wars.
I don't think that's completely irrelevant, nor do I believe it's 'sloppy thinking'. It's taking the information at hand and selecting the most likely outcome, then weighing it against the likely outcomes of the other candidates.
Having something be important to you isn't sloppy thinking. Making the best choice you can based on limited information isn't sloppy thinking.
Thinking you know something there is no way you can know is sloppy thinking.