Multiple Asynchronous Task in a BPM Flow

Firstly,Can a HTTP Task be executed Asynchronously?

Now Suppose I have multiple Service Task/HTTP Task in my flow Like

Start—> ST1 —> HTTP T1 --> ST2 --> HTTPT2 —> ST3 —> HTTP T3 —> DMN --> END EVENT

ST-> Service Task
HTTP T --> HTTP Task

Suppose I made tasks ST2, HTTP2, ST3, HTTP3 to be asynchronous , So whether all of them will be executed by same asynchronous job executor , or they may be executed by different executors depending upon course of execution?