try to play VS bronze team in squad battle and choose Legendary level you will find the bronze team run like it is final game run everywhere very fast and they tackle very well and even with low Strength they will win the ball and it is logical because you know that ea will rise the AI and ea told you that.
however in online mode it must be every players in the same condition but you will find something strange for example NEYMAR Strength is 49 but in the game sometimes he become stronger than BOATENG and his Strength 99.
why I said that when I start use TOTSSF players I was in div 2 I have fast players like AUBAMEYANG 96 pace 99 Vardy 95 pace 99 and they have great stats in balance ans agility Except AUBAMEYANG his agility 81 and with engine card become 91 they were slower than any CB heavy to move and sluggish and now in div 5.
it is very similar to what happens in off line Legendary level.
When we see things this way it will explain to us why the opponent is sometimes faster and his players like legends even if he uses mid-level players.