It won't happen, but Lukaku is a proven premier League goalscorer and Conte player. Always have 2 out of Son/Kane/Lukaku on the pitch would be very good for us, sign Eriksen too so one of Eriksen/Kulusevski is on the pitch as well and our attack would be fantastic, especially with our improved wingbacks.
Kane is also so good that if you wanted all three on the field, Kane becomes number ten, Son and Lukaku ahead of him coming from the left and right inside forward positions (a lot of Lukaku's best football is when he comes in on his left foot, running from that right channel off the ball).
But I don't think it will happen unless Chelsea are desperate to sell and have no good offers.