1. Newly acquired players need time to "gel" with the club and achieve their full potential. They may play poorly at first for no apparent reason. (I think it's plausible)
That's a myth. It's a question that I read some other times and it has been answered. But it's so obvious for every one to see that, because every one is buying new players almost every season so can see that some players playing good from the beginning, some others later and some never. It's a lottery.

Beyond the Myth -
A new created team need time to perform well ?
I 'm not talking if you buy 11 players and pump them to 7-8* but a team with 5* players from the market.
It happened many times to me so I believe that it's something more than coincidence. This season, I 'm starting with a new lv1 team, I bought 12 5* players, and hardly can win 3* bot teams .
The suggestion is to keep the first post updated with the myths that have been tested/discussed. There are currently only four myths listed in the "resume", even though there are 8 pages of discussions. I think inconclusive or "in progress" myths should also be listed.
The thread is still open and alive, so I 'm waiting for more opinions.

All those things about training and fast trainers, have been answered in my Guide. I know, it's boring to read so long thread but it's also boring to me to repeat the same things.
So far, training and fast trainers is one of the few things of the game, that are so clear and steady.