Playing the Xavi role =/= mirroring Xavi in exact style. He controls the play in Bayern, who play a similar possession game to what Barca have played in years past (with the key difference of being more wing oriented than CF). In that midfield, he is the general of the passing play distributing the ball around and setting the tempo.
To make the comparison more clear, let's stop using current Xavi as the pillar for what the Xavi role is. Let's say that both players are the midfield conductors for the various teams. Both teams play a similar passing style, both midfields have a similar structure, therefore the comparison of midfield conductor can be translated between the teams. In that role: Kroos is more energetic in movement and controlling the buildup play, quicker in playing passes and opening up the game, and has a better defensive workrate. Xavi plays more passes and remains effective at the role that is required of him, but is much slower and less dynamic at it which forfeits him from being described as "brilliant" or "great" currently. Head to head comparison, Kroos is the better player now and can still re-add a scoring dimension to his game.
