Regarding randomization, the HCQ + Azithromycin study showed good results despite the control group being 14 years younger. Sex was about equal so no male/female imbalance. It’s clear that older patients have worse outcomes, but this study measures viral load which also can change depending on the stage of the disease.
There were 6 patients in that group. No mention of how they were selected. Some patients dropped out of the treatment group because they died or went to the ICU. These could affect the numbers significantly.