Thing is, the Matip/ Lovren partnership sort of does have that complimentary skillset to a point, with Lovren being the more physical presence and Matip the cerebral, passing compliment, but neither seem great in the air, and I suppose the biggest issue is that neither seem all that good at basic defending at times.
I have more long-term confidence in Matip, but even he seems absurdly overrated by many.
As for Terry, he has always needed to play next to a defender with pace, given he has none. He can do every other part of the job brilliantly (well, he used to anyway) because he can certainly mix it physically, he's great in the air, and he's also superb with the ball at his feet. His vulnerability to players running at him, and quick movement has always been there.