Let the appointing authority exercise his prerogative under the Constitution and existing laws to appoint whoever he feels can effectively support his policies and programs. After all, if his appointees would fall short and fail to deliver, the ultimate responsibility lies in the President who will be accountable to the people.
Having said that, the check and balance, at least in regard to the appointment of Cabinet members who are subject to confirmation by the Commission on Appointments, is available under the Constitution.
Without sounding biased since I also came from the Armed Forces of the Philippines and the police, what if those appointees would also question the wisdom of appointing too many lawyers in government? What is important is the competence and integrity of those appointees, and not their professional background.