Recommend that you treat everyone involved in the process, as having input. IE: the staffer receiving your application package could be a seasoned, long time employee, military Veteran staffer who works behind the scenes with much responsibility, and whom the nom source relies upon for their experience. Alternately, the staffer receiving your application package could be a first year staffer who is learning the ropes, with little to no experience and no input at all. One never knows!
Obviously, there are standards, procedures and a process for selection. And ultimately it is the the congress person/senator that selects. So it would be proper to approach your own process under those parameters. There really isn't any reason to have intimate knowledge with their individual process.
Of course, if you insist on knowing, you could inquire of them. But I wouldn’t recommend that….its a bad look, imo.