By Shard 65-66 you’ve gone well beyond the difficulty of the Crucible, so I’m not sure in what way it is balanced worse.
You seem to have set an arbitrary goal for yourself in the Shattered Realm and if it’s not as easy to achieve as 170 Gladiator Crucible, then it is somehow not as well balanced. Believe it or not, Crucible is in the 55-60 range of the Shattered Realm, at best. Anything beyond 60 is pushing your limits, where anything goes.
Coincidentally, the full Shattered Realm set is earned by Shard 60.