Be particularly careful about your hold.
If the man's right arm slopes downwards from the shoulder to the lady's shoulderblade, and if the left upper arm slopes down at the same angle (so that the elbows are at the same height), the upward slope of the left forearm to the handclasp will naturally be at around the height of the lady's eyes. The lady's right arm should be almost 'laid' along the man's right arm, with contact points the the top of the lady's arm, and the man's wrist, and again at the top of the man's arm with the lady's fingers. The elbows should nearly touch: we should not see a gap between. The overall impression is one of balance on the two sides of the body. (Obviously, we make the usual adjustments for Tango).
Check carefully, using a mirror, but your basic posture and set-up is quite pleasing, and you have the potential to develop quite a big top line for the swing ballroom dances. I don't see any reason to worry about the height difference.