Is it good to use 1 second task(since i m already using it) to merge all other tasks so there's only one task in the core or divide it in multiple?
No need to change . Whatever most convenient for yourself is good .Don't worry about performance here.
But wouldnt it be degrading if there are like multiple tasks running while u can just merge them in one?
If your tasks are not managed by the server, they are managed by yourself instead. They eventually still need to be managed. Why do you think handling them yourself will make things faster?