I would rather him come over with this aggression but it will be down to Carlo and JT to tell him when its right to use it and when its not. Its actually quite the opposite, Chelsea fans love a tough player and if things arnt going right in a game somtimes a rash tackle gets us off our feet and gets us going.
In relation to your last point Ivanovic was immense at right back last season so i suspect he will become our perminant right back. Then we will have 4 centre backs in Terry, Bruma, Alex and Luiz, 3 right backs in Ferreira, Ivanovic and Bosingwa and 3 left backs in Cole, Van Aanholt and Zhirkov. Also Ivanovic can play centre back, Bruma can play Right back and Luiz can play anywere along the back 4 so its very fluent.
As i suggested the deal will include one of our youngsters plus 21million. Will be either Rajkovic, Matic, Borini or Van Aanholt (i would hope on loan).