Now when Saul had taken the kingdom over Israel, he fought against all his enemies on every side, against Moab, and against the children of Ammon, and against Edom, and against the kings of Zobah, and against the Philistines: and wherever he turned himself, he put [them] to the worse.
The inspired author here freely admitted Saul's ability as a "valiant" soldier and his ability to defeat God's enemies.  Thus, the reason assigned by the Lord in his appointment of Saul to deliver the people from the Philistines was indeed a good one.