I have no idea whether it applies in this case, but I've certainly known a few people (including myself, at times) who've intentionally taken somewhat contrary positions (even ones they/I knew were, shall we say, less than optimal) to give the "new guy" a chance to explain his position, and really follow through on the arguments in its favor.
At least in my case, that was often because I knew there were some others on the team with a little bit of a passive-aggressive streak (or something similar anyway). If/when a new idea was accepted too easily/quickly, they soon started thinking of objections to it privately -- but rather than openly voicing those objections where they could be considered and answered, they frequently quit carrying out their part of the plan, or in even (usually subtly) sabotaging it.
Voicing the objections up-front and openly gave the idea's proponent(s) a chance to reply to the objections. If they hadn't been openly voiced, the passive-aggressive types would have thought up the same objections -- but would not have voiced them openly so the proponent could reply. In their minds, the problems quickly became insurmountable -- at which point there was obviously no reason for them to make any effort to overcome the problems, or even stay out of the way of others.
I should add, however, that in most cases the objections had at least enough substance that the plan was improved at least a little bit by them. The mere fact that an idea is good doesn't automatically mean it's flawless. Again, however, it's at least as much about perception as reality -- a few minor modifications to a plan can get people on the team to think of it much more as their own plan to which they made a real contribution, removing a lot of the perception that it's entirely the product of "the arrogant new guy."
From your side, it's worth considering perceptions as well. Even minor changes in wording can make a big difference -- I know the phrase "best practice" is popular right now, but I generally try to avoid it, and I think it's at least worth considering doing so as well.
Saying "XYZ is the current best practice" directly implies that alternatives are inferior (and, quite honestly, makes you sound a bit arrogant). Saying "I know it's kind of new and untried, but I wonder if we could consider something kind of along the lines of XYZ?" will still get people to think about using XYZ, but without nearly as much implication that what they're currently doing is wrong, that they know less than you about the problem at hand, etc.
Which do you think is likely to work better in the end: the best idea being seen as belonging to only one person, and "shoved down the throat" of the rest of team, or a good enough idea, with the whole team behind it?