Hardware requirements HANA

We are looking to install HPE systems. Where other brands are required to have a storage pool from 5 ssd's 400gb each, HPE systems need 5 times as much storage, for what reasons? The difference is quite excessive.

Also, a raid configuration of 4 x 1.8TB in raid 50 modus is required, however, raid50 can only be created with 6 drives minimal, so that woulde be a mistake.

Is the description in the guide wrong? What would actually be the minimal requirements?

Thanks for your time and help.

Kind regards,

Mark