Depends on if you want good players now or good future hall of famers.
If you want good players now the combine score is a direct reflection of speed = 40 time, strength = bench, agility = cone drill. And the star graph is also a direct reflection of the current skill set. Draft according to speed then star graph.
If you want to build for the future, you need a way to mark all players with great potential. I scout the players with the best potential at every position. Then on draft day, (when u can't see potential) I know the players I have scouted are high potential.
Since the season is almost over write down 2 players at every position with high potential. Scout as many high potential players as possible.
The reason you need to identify high potential is the players with the highest potential might go in later rounds. Think Tom Brady, Tony Romo etc... These players may start out weak but will progress to become great.
A lot depends on how many seasons you guys run. Some players with good potential start out slow, so if youir only gonna run a season or two they are not needed. In that case use the star graph and combine scorres. For long term franchises go with potential.
Who is the top rated QB in your current draft?