Actually I myself am on the border between the ENTP and INTJ types. Similar to the way others and you seem to view it, in the work place you find yourself leaning towards the J type and with friends your more P type. I myself am very much like that. However I generally lean towards P type as I much rather try to avoid looking too 'J'ackassish to co-workers. However that doesn't mean I won't, when pushed instantly switch and demand to straighten matters up in the work place to increase efficiency. Generally though, being that I switch to INTJ rather than ENTJ I'm more focus on my own efficiency and let others burn in their stupidity, but that's just me working out of spite.
Overall I'd probably say your more likely to be ENTP, with a fair balance in your functions towards the J function. It actually is a good thing not to be too far into the P type cause you get too much P and you lose focus on just getting things done and just kind of leave a wake of half baked projects. Plus without the self motivating aspect of J types you'd never push yourself to higher positions as easily within the work place, (relying on others to eventually promote you based only on performance which is limited to what they alone see from you,) so utilize that J type for personal gain, (and to be wary of the boundaries or consequences of breaking rules,) but know how it will affect those around you with your P type and you could potentially move beyond even some of the most aggressive of ENTJ's while maintaining your good reputation with your 'followers' (as I like to call my audience).