I copy people occasionally too, but more the way they talk and some of their expression than the whole high-level "communication style". I also try to adapt to whatever communication I am doing. For example, my mother is very good at smalltalk and that kind of social conversation, I tend to speak like her when I have to endure such chitchat. Another friend of mine is a very good orator when he is explaining things he is interested in (often he is even a bit too good and engaged in what he's saying, to the point where I sometimes wonder if he may be on the spectrum. He does not really seem to have social impairments but clearly he is even more hyperfocused than me.), I copy his mannerisms when I have to expose my knowledge in public. A coworker of mine has a slow and very soft voice, in an almost hypnotic way ; it is sometimes annoying (when you want to get to the point and he's too slow) but it's both clear and very soothing, so I try to adopt his manner of speaking when I am trying to explain something to someone who doesn't get it (instead of getting irritated). When I am into deep, important conversations or decision, I use various "heroic" movies and videogames characters to sound like I am really into it.
So my advice would be to vary your models or to find another person to mimic for your work role. There are ways to be assertive without being bossy, and there are probably some people around you who embody them.
On the other hand, in the same line of what ThorAlex says, being a good leader (or a good person in a professional hierarchical environment) is not something that comes naturally even to many NT. Many good bosses used to be bad bosses and eventually learnt to get better. Being in a hierarchical structure and communicating with another person in it in a way that is respectful both to you, to the other person and to the social structure is a non-trivial social skill for both NT and autistic people. (The problem is, not so many people are interested in actually learning that skill, because many NT people don't care about the other person and most autistic persons don't care about the structure.) But there are training and self-help books on the topic.
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ouroboros
A bit obsessed with vocabulary, semantics and using the right words. Sorry if it is a concern. It's the way I think, I am not hair-splitting or attacking you.