Why would that be fairer? Apple chooses to compete in the market with a clear lineup of 3 device-classes that each have multiple models differing in the amount of memory only. They don't offer low-end models. They obviously think that this is the better strategy. Samsung thinks it is better served by building more models to serve a higher range of customers. It is perfectly fair to compare which strategy fares best - and by number of units sold Samsung seems to be ahead. By revenue, Apple seems to be ahead. Whether that balance is going to tip is an interesting question, but it's not answered in this article.

Unfair would be to compare the number of macs sold vs. the number of android phones sold since those devices don't compete against each other on the same market.