C-16

I was looking in my copy of Locomotives of the Rio Grande (CRRM) for something and got distracted in the C-16 section.
In 1882 D&RG had 85 total C-16's of which 28 were Grant.
In 1887 D&RG sent several to the D&RGW/RGW. They had a total of 74 of which all 28 Grant were still in D&RG hands.
In 1892 many C-16's were sold to RGS leving 53 total C-16's and still all 28 grants were in D&RG hands.
In 1927 the first of the Grant C-16's were retired (23 remained - 13 were grant)
In 1941 the last Grant was retired (223) while 3 Baldwins remained (268, 271, 278).
Is it a coincidence or is there a reason why D&RG/D&RGW hung onto the Grant built C-16's over the Baldwins?
Thanks