I think correlation and UE pairing has nothing to do with high SINR of the 2 UEs.
And it is not just 2 UEs, can be up to 8 UEs in Huawei for pairing in NR.
8 UEs meaning 16 PDSCH layers for 8 paired UEs in teh ideal case.
Of course in reality we will seldom see this, but it is common to see 3-4 UEs paired in 6-8 PDSCH layers.