Madrid are already managing his minutes (<40 games a season for the past 2yrs) to prolong him in la liga and you want him to come to EPL, where there are more games and is physically more demanding, and still give you 2 seasons as a starter? He definitely cannot cope with the physical demands needed to do so. Bayern and Juve play in a slower leagues, so yes an old man can still perform for them.
You are the same guy that accuses Mourinho of playing Pogba out position but now want us to buy an aged Modric to play him out of position late in his career. His mobility and acceleration are a big part of his current role, and his passing range is not wide enough to be a DLP. So he will need at least a season to settle into such a new role. He is simply not worth it.
Modric is past his prime and unless he is available for free and ready to be coming off the bench, he is not worth the risk.
Also we dont need a DLP. Pogba is the playmaker, for better or worse. He has the ability and has shown it this season. what Pogba needs is a solid DM with decent abilities on the ball. That covers up his defensive shortcomings and gives him more offensive freedom.
Even if you want a playmaker, there are better options like Veratti or younger ones like Weigl or Paredes.
We should be assembling the core of our team that will last for the next 3-5 seasons, not inheriting other clubs retirees.