So if i did the combine it scouts all players. And the group demo only scouts 1-2 ball prospects. Wouldn't that be a waste of money?
The combine doesn't "Scout" any of the players. It only gives you information about their age and height. Nothing more.
If you want to learn their Star rating (current skills), Position and see a box score, you will still need to "Scout" those players.
If you don't do the combine, to learn age & height, you would need to Interview a player after Scouting him. The interview would also provide a Potential rating as well as a Grade rating (really a fine tuning of the Star rating).