Personal staff yes, the Committee staff, the bureaucrats that actually run the nuts and bolts of the Congress, I have been told do not change much. The people who actually run, say Congressional Budget Office or things of that nature are Careerists. I do not think the Repbs have made nearly as deep and wide a house cleaning in the Congressional Staff as they probably should.
Nor did I mean new congressmen would keep staff from the other party.
As I understand it, some staff will remain, even if temporarily, to help with transition. Some of those will be retained if they impress the new guy and others will be brought in as needed or desired.
New congressmen will also have 'suggested' staff by various interest groups who have a presence in DC.
Agreed, that is the way it works. It is up to the Pary leadership to make whatever changes are deemed necessary. Some of these careerists use their staff positions to get other jobs, e.g., George Tenet.