I see quite a lot of potential in this pairing and I quite like them - good movement and strong attack, fast and decent defence but they have some obvious weaknesses they really need to overcome to be among the best.
I feel there is an element of arrogance/over-confidence, a desire to show off a little too much. Yes, it is good to have confidence and self belief, but it needs to be tempered. Too much will distract your concentration and ultimately performance. You can see both of them at times would stare out the opposition, or excessively delay their opponent's serve etc. Or going for a "lap of honour" walk after pulling off a difficult shot/rally.
The recent match against Ivanov and Sozonov is a good example. They were doing it a little too much in my opinion and they were clearly trying to play the mind game.
LJH is, for me the weaker of the two. He is terribly inconsistent and has a relatively poor touch, particularly in the mid court and net. He tries to hit very steep smashes which when he pulls it off is fantastic, but it leaves very little margin for error. I like the way he mixes up his placement of the smash a lot and is not afraid of smashing close to the sidelines. But the amount of times he has put the shuttle in the net is quite concerning, particularly as most of these errors were unforced. He always seem to want to go for high risk, almost showboat shots to (seemingly) embarrass their opponents. It is clear that when he does pull of such a shot, he really feels good about himself. We all should feel good about playing well, but we shouldn't let it distract our concentration.
This attitude in my opinion is a little immature and is holding them back from their full potential.
If they can sort out this attitude and consistency, particularly LJH's shots in the midcourt/net area, they would easily reach the top ten.