Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action
Human Factors; Procedure
Returning to SDL.  Passing SCOLE [intersection]; we were cleared direct TIRON (standard instructions from ABQ Center) and handed off to Luke Approach. After passing TIRON; was given a descent to 6000 feet on a 060 degree heading. After leveling off at 6000 feet on that heading; TCAS indicated traffic at 12 o'clock 3 hundred feet below us approximately 5 miles. The Pilot Flying spotted the traffic briefly. I did not; however; I called Luke Approach and asked for a turn to the east to avoid a possible conflict TA/RA. We were issued a 050 degree heading; not enough in my opinion to avoid traffic. I told the flying pilot we were going to get an RA. He agreed. I was frustrated with Luke Approach at this point as I expressed my concern of a traffic conflict and we knew an RA was about to occur. Shortly thereafter we got an RA with a climb command which we followed; and I alerted Luke Approach of this. The RA cleared at approximately 6500 feet; and then proceeded to descend back to 6000 feet. As described; NE of TIRON is a busy flight training traffic area. It is also called the NW Practice area.  I have always wondered why Approach Control brings us down so low in an area where there are a lot of training aircraft. Maybe somewhere around 8k to 10k would be more appropriate until we got closer to the PHX Class B. I understand there are arrival and departures out of PHX that they [are] having us avoid but those aircraft are generally around 10k and are on an IFR Flight plan.  I think another option would have been for the controller to have understood my concern for traffic and given us a farther turn to the east such as a temporary turn to 090.
Corporate Captain reported LUF Approach Control issued routing through a busy training area.