Think defending is an area that he lacks actually. I've often found him as useless as Sambi ans Xhaka defensively. Tidy player but Ndidi has been covering for him a lot.The reason that Tielemans is exciting, and a significant upgrade to our current options is that he has a rare ability to both be very productive in terms of creativity and goal threat, but also have enough bite and defensive nous to play deeper in a midfield two. Obviously a different player to Guimaraes (who I really rate), but apart from his PL pedigree he also has much better offensive output - he's averaged around 5 goals + 5 assists from central midfield for 3 seasons running. Bruno can't match that (although as you said he brings more defensive balance). Tielemans (was) 5th in the league for open play chances created this year and of those 5 players has by far the highest number of tackles and possession in the middle third of the pitch. Not saying he's a defensive player, but he's not a lightweight like most attacking mids, but he still gets the numbers.
That's why you pay the big money for him and I hope we do if there's a chance.
Leicester City have turned their form around in recent games, but Youri Tielemans has kept his standards remarkably high in 2021-22.theanalyst.com
Doubt we'll be hearing as much praise for him if he didn't have him doing the dirty work.
It becomes more evident when he plays for Belgium.