i usually feel uneasy talking about myself in a recommendation letter for myself as well. mine was essentially strong points in reference to my career.

care sharing your topic strategy?

This is a common practice among applicants and there probably is no harm in doing this, as long as they consent to it. Your former managers are probably very busy and won't have the time to write well-constructed and iterated letters for you. You would be the best person to know what qualities about your work experience you should present to the university you're applying to. If you let your bosses write the letters themselves, they might not be able to zero-in on those qualities.

You will probably need to have several meetings of going through drafts with your former bosses. They might be able to provide helpful input. In my case, my ex boss reminded me of a long-forgotten project I did that sounded very good to mention for an MBA application.