Our folks are very nice to new comers so they are all correct. In terms of scout players, this is a mystery forever; trust me that after you play for 20 seasons you might still question: is it worthy?
Well, can I give you a stupid but very sincere suggestion? Look at your team and find out if you really need one player who must be there to make your team complete. If the answer is yes then ok go to the scout list and choose the one you need. Now here is what I suggest: he must be no older than 24 years old, otherwise he will be too old to stay for a few seasons; he must be only one point to 7 stars, i.e, if you see a scout player who is not X4 or X9, please be careful, he might not be good; then check the price, choose an expensive one, because that will allow him to be trained a bit faster than others - now please note that I meant faster than other scout players in the scout list, not other fast trainers because all scout players are actually slow trainers.
These are all I want to say about scout players. You try it and you taste it, if you feels good keep going until you feel that you should stop buying scout players. Or you might benefit from it and keep doing so and make great achievement, who knows?
But if you play on mobile, you might be able to see something called recommended players that selected by your assistant manager. There are always 3 players with their past games stats so that you can check their ratings and their forms, goals, etc... You only need to spend tokens without any cash to buy these players and among them the one costs most tokens is a fast trainer. If you play on PC, you won't see this for sure. These players are not scout players but they could be better choices; again it depends, not everyone can see this option on mobile.
Overall, you really have to try by yourself, all of us can give you our opinions but you will feel that we are all correct or all wrong. Personally I bought scout players before, if I remember correctly I bought 4 of them and it was half and half in terms of quality, so 50% successful rate to me. I know others have either higher or lower rate but it doesn't matter, because no one has 100% successful rate.
Good luck and welcome!