Why are the units in the carousel ordered by cost/rarity? + a suggestion

Is there a particular reason why the units in the carousel are ordered by cost rarity? I find it a little strange that when the carousel opens in later rounds, one player often gets their first pick of which 5 cost units they prefer before the other player can even get to them (and this often isn't the last place player but the second to last place so I'm guessing it's just random).

If the reason is not a gameplay decision, I suggest that the 5 cost units be placed on opposite sides of the carousel so that both players at least have priority over one of the units (This is a little more awkward with only 9 units in the carousel now but shouldn't be a huge problem). Same sort of reasoning applies to all the carousels (besides the first) and to units of each cost.

If there is a good gameplay reason I'd love to hear why or learn about other considerations for the carousel design