Improve flames in a rendered video - using After Effects?

I have had a video made from a 3D render of a coin design spinning around (it's 11 seconds long and 1920x1920 resolution mp4), there are 2 small fire-pits in the scene and the flames coming from them look a little bit "wonky" - I'm hoping a video editor could use something like After Effects or similar to fix/improve these flames. Everything else in the video is perfect, I just want the flames to look more real.

I have attached a few image crops of one of the flames - the flames do get obscured as the coin rotates, so I do not think it's as simple as just pasting another flame on top, since it will need masking or something as the coin rotates - I don't know though, I know nothing about video editing, which is why I'm looking for somebody to help me.

I would like this to be started and delivered within 24 hours if possible.

I will only upload the actual video to be edited to the winning freelancer.