I have scout players who are 6-7-6-7-6 but I still keep them because they are useful. And scouts will have an off season, most, not all. If you are lucky you can get a scout who will deliver every season, like my Matias Madrid and Rick Hunter (both wingers).

But for non scouts how I decide on which to buy are

1. Previous match stats (if available)
2. Value vs Age (look at your scout list and the price of a 5star of similar age in the market shd be 2-4 mill difference than one on scout list)
3. Age between 22-25
4. Height (I love tall players because I have players who take good set pieces)
5. Either footed
6. I like his name