As mentioned by a few already, 25 ads for greens should be taken first.

As many as 5 of the remaining 15 ads could be used for x2, and so this option could be used to the best effect to boost all new joiners at the start of a new season with pre-planned better timing of ads viewing.

Eg. Roughly 1 hour before daily refresh to boost x2 for 2-3 times, and then right after daily refresh boost x2 for the other 2-3 times. All new players should gain max team player bonus after daily refresh. All we need to do is to calculate in advance to both prepare sufficient reserves players to make a training group of 8 players and also accumulate to max conditions beforehand.