As a more advanced manager in higher level when you may have saved up hundreds or even thousands of blues and reds, those packs may seem useless to you.
For a new manager who start with 20 reds and blues, and could barely upgrade the pitch or medical facility yet, and also may just have enough good players to cover first-11 and a few good subs, it is a constant nightmare when a 5-day injury pops up some 5-6 times a season. That 100 reds needed per season do not appear from nowhere. Reds gained from ads also means money ads are not taken. Consequently, stadium unable to be upgraded sooner also means all facilities, including pitch and medical facility, cannot be upgraded.
And if we are facing similar level managers in quarter finals onwards, lower level managers’ defenders are unlikely to match with the relatively stronger attackers. That means receiving cards being likely when using easy tackling is not viable. For example, I have a 120% ST, and nearly every game my opponent receives yellow cards and around 1 in 7-8 matches they would get a red. Earning reds through matches are not that easy in lower level matches.
Blues are generally better, but then if we draw or lose a few games, there would be a drain on that too. Final matches in tight leagues, semis and finals would cost a lot of blues to max as well.
Blues and reds could be used as part of the inputs for youth training now, so they could be useful substitute as greens for new managers when most would be trying hard to save the precious greens.
The money prize of winning both the league and cup cannot even buy us an 18yo 90% FT in season 1 and 2, so the money ads are absolutely necessary to generate the funds needed for the FT purchase. A new manager would be doing extremely well to keep 4 18/19yo 110% FT, plus sufficient funds to buy another 11 good players for next season, by the end of season 2. And that is before the stadium upgrade cost being taken into account.
I do understand that more experienced and higher level manager like yourself would feel anything other than greens are useless (They could well be when we have several hundreds or more
). Using them for youth intensity training instead of greens is possible.
5-10% advantage is very insignificant if a lower level manager only operates on a AML/ST/AMR(+AMC) basis when his/her strongest players readily gives away their likely formation and tactics. Playing a 4-1-4-1, 4-2-3-1, 4-1-3-1-1 with defensive, long ball and counter could block all space for wingers and win with counter goals with ease. Wins about 3 out of 4 matches in platinum association with 5-10% disadvantage against these offensive combinations.
A manager should win most when they follow your advice on squad building though.