I'd rather sleep 🙌... Two Mog on one side with one mdg in support.... I pass in short pass with more than 200 bonus despite that nothing 🤦🤦.... Federation matches disgust me these days... It's the third time I've played with the same opponent, always favoured by the same starting line-up

Is there no way to reposition players? I ask the admins to enlighten me thank you 🙌

Players arrive in the federation with the position they were assigned at their home club, so it's not uncommon for flankers to find themselves doubling up.
Only the opposing coach can (and must) change this to keep things in order.
If he is not connected, the aberration remains... but if he is connected and does nothing, he can be punished because he is consciously exploiting a loophole.

If I have a titular mog and mod in the middle of a match and I take 1 of them out and the one in the starting 11 takes its place when the match is over, I have 2 mogs on the same side.
For example, I take the mod out and put my mog in its place.
I'd have 2 mods after the match

Correct Lens
And you need to make the correction as Blagoje explained.
If the opponent is not connected, you can contact an admin who will make the change for the opposing team.
I've already done this several times in federation matches.