hmm...
are any of the auxillaries slightly disloyal to Rome? would any of them join us without later betraying us?

anyway i think that we should kill the legionaires definately, keep Longinus prisoner for barter later, and if possible recruit the auxillaries for our own cause, if not kill them as well. so basically 2a. Sending a few heads or disfigured bodies is not going to scare off a 200,000 strong army, if anything it would anger them further to commit such atrocities to our own troops in the future.