I'm on my fourth transfer now in the Microsoft system. Started at Customer support, got transferred to technical support, then to commercial support, now I'm going to sales support. Lol.
Dell was completely unable to answer the question. They went on about all sorts of hardware raid methodologies but finally admitted after an hour they did not know.
I'm on the phone with Microsoft sales support and the representative says neither he nor anyone on his team knows if Windows Server 2019 can mirror two hard drives together into a RAID 1 mirror.