Don't you consider a warmonger alternative: Warrior + Warrior + Warrior + Worker + capturing AI worker by your initial warrior + first warrior you built. Second you built (actually third) warrior should be moved somewhere between AI and your capital to provide a captured worker with defense against animals. Fourth warrior should defend the city.
Research priorities - Pottery (which allows Granary) or BW which allows chopping. If pottery comes first, built granary before starting settler (which makes whipping more effective) and start cottege spam by your two workers. If BW, chop your settler ASAP and look for a bronze site. The priority depends on which area you capital is, if there are too much forest - BW comes first, otherwise Pottery.
Please note - on Emperor level, AI workers are almost always guarded by one archer. So one of your warriors is going to be killed with 90% chance. Anyway, one warrior per one worker is a good investment.
Benefits - perhaps this plan is few turns slower than the "build worker first" plan but your neighbor will leave you much more land and he is going to be a easy prey as soon as you've bronze. Just move your survived warrior (which get some expirience with archer and hopefully promoted to archer killer) to some forest and fortify. Don't attack the city, just sit here and look. AI will build new worker but while your warrior is here, will stay in the city. Move another warrior (the one which provided captured worker with safety) there as soon as the captured worker is in a safe place. Result - your friend needs a lot of archers to kill your two fortified warriors. And all this time his new worker will stupidly sit in the city afraiding. And all this time you will mprove your territory. BTW, you can turn AI capital into your "worker factory" and "military factory" (which I described in another thread) instead of capturing it if city maintenance is going to be an issue.
I am not sure about higher levels but it works on Emperor just perfectly.
And if you play Incan, don't waste a time and capture a couple of AI capitals, workers can wait. Four quechas of level 2 (combat 1 + cover, quite easility to promote them by hunting wild animals) will kill 2 fortified unpromoted archers (in city with +40% bonuse) with ~80% chances. Five quechas will have chances better than >95%.
P.S. I am playing Maraphon games. This is important because, at different speeds, I can imagine it takes relatively longer time to move your units, including the captured worker.