"The boss wants to put me on the top and fire another colleague!" Because another colleague is too flat, the base salary is 8k higher than me but the performance is not as good as me (I am currently 10k he is 18k, before being the Lord

"The boss wants to put me on the top and fire another colleague!" Because another colleague is too flat, the basic salary is 8k higher than me but the performance is not as good as me (I am currently 10k he is 18k, before the supervisor treatment recruited), so the boss's current idea is to fire him, give me an assistant to train me to be the head of the department (so that I can take over the colleague's work, get more commissions) or recruit another experienced operation.

The current base salary is 10k, and the salary will recently rise to 13k due to performance standards. After managing the entire department, there are more things to be responsible for, but the basic salary should probably be 13k, but it will be added. At present, the management post is a bit out of its own comfort zone, although the career planning is definitely close to the management post. Do you have any good suggestions?