Well, not knowing enough in depth about your Work Experience (what you actually do and what your achievements are) it's a bit hard for me to say whether it is good enough!
But keep in mind a few things 1. Your four years is for sure enough for you to apply. 2. Lots of people apply without leadership experience. If you know for SURE that you will be promoted to a managerial position and don't mind staying at your job for another, yes that can help nicely when it comes time to apply, but otherwise, I don't necessarily see it as an advantage to have another year and you should apply now.
Your school list seems good, and your evaluation about right (again, the info you provided is a bit rough, but it seems reasonable). In addition to the schools on your list, I would suggest Kellogg and McCombs for their strengths in production management as well.
If you'd like a fuller evaluation, you can contact us for a free consultation: http://admissionado.com/mba/free-consultation/
Look forward to hearing from you,
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