Since the manager is the only person who knows best what kind of players he needs the most at the moment, why not give him the control over the recommended offers he get?

My proposition is simple. Make it possible to give orders to your assistant to search for players with specific positions. You wait up to two-three days and then the assistant shows up with what you exactly need. After the offers times out / or / you buy a player there's one day cooldown, or you can begin another search right away.

Recommended offers is a great tool to seriously strengthen your team, but there's no reason it should be random. Giving managers more control over it is always better!