I wont say I'm an expert in this, but recently, I mounted tires of same compond in two combinations: Hard wheel with soft insert and soft wheel with hard insert. I find the soft wheel with hard insert is more forgiving, both to driving style and small bumps in the track. But the hard wheel with soft insert, wow, what a handling. Much grip, yet precise. The car handle more responsive, tending to the aggresive.
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250