The link that you provided largely confirms what parent said: it puts WooCommerce ahead of Shopify in terms of store count, with a number (4.34M live stores) which is consistent to the one mentioned by parent ("over four million stores").

> They're close on number of installations.

2.84M vs 4.34M is quite a wide margin, wouldn't you agree?

It's true that the link puts Shopify at roughly 10X in terms of GMV but parent did not claim otherwise.