I suppose he's a defensive box-to-box midfielder. Whereas someone like Vidal or Nainggolan would be a rounded box-to-box midfielder, because they can do the defensive and offensive plays. Then you have someone like Khedira, for example, who is more of an attacking box-to-box midfielder or classic attacking CM.
Only problem with these players is that age is often important for their best level, so if Allan becomes available at 29 we wouldn't see his best level for many more years.
i rated kurzawa back in his monaco days, but he never managed to settle at psg, and his injury record is disappointing. add his salary to the mix and the fact that we have pellegrini out on loan in his position, and it looks like a questionable move already. we're creating a problem for a position that looked to be set in a couple of months. unless alex sandro is sold, we don't need kurzawa at all. and if sandy is sold, kurzawa is an underwhelming solution, regardless of his injury record.
He is right tho, questionable addition to our team, but Kurzawa is little upgrade in talent and health. We need to see whole contract or deal until we judge finances, but 500k more in salary is not moan worthy.