[DM01-06]Aquan+Cyber brain option?

I understand that in DM01-06, aquan+brain functions very similarly as an OP draw engine (alternative to Reef) albeit restricted to Light/Dark decks.

What reasons are there to run aquan+brain over marineflower+steamstar+reef? Feels like Reef engine is as effective, if not more effective in literally every scenario.

For reference I am talking about this version of aquan: https://duelmasters.fandom.com/wiki/Aquan

and brain: https://duelmasters.fandom.com/wiki/Cyber_Brain

The meta kit for mono water seems to be reef+streamer+brain

Why then are there still sample decks that use aquan brain over reef?