とは思うのだが、口に出すわけにもいかんか。My personal translations would be these: Those are my thoughts on that (previous statement), so I might as well say it out loud.
出動後はそうはいかんぞ。。。 "but after they move out, how it goes..."
I'm not sure how "いかん" works. Dictionnary says it means: how, in what way. Or is it an abbreviation of "いかない", or even "いけない" or something else?
Thanks in advance!