To further clarify this point.
This used to be a really common occurrence and IMHO logs hiding non standard comps from the main rankings did more to limit the frequency of 1 healer or 1 tank runs than almost anything SE have managed to do over the years.
The standard comp switch happened during the creator tier if I remember correctly, and it was in response to it almost becoming the norm to drop a healer for easier turns like A9S if you wanted any shot at the rankings. You can confirm this yourself by comparing the number of non standard comp runs in 3.4 vs 3.5.