To be honest, can't really help you that much with the RAID stuff at all. I've very little practical experience with linux and softraid.
Can only provide a few pointers by going through the logs and information you provided.
In the previous post, the error was about failing to mount partition with the UUID b3df7655-a5a1-4a4b-bc9a-3c5dff81c24d as / (or /sysroot during initrd).
According to the by-uuid mapping, this is sda5.
/dev/disk/by-uuid:
total 0
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 2844fbb9-df92-4d77-afde-efe101d42166 -> ../../sdc1
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 37e7d55d-fbbe-42be-8f96-7e867e32b479 -> ../../sda4
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 8500-9080 -> ../../sda1
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 95c143bb-fdef-4cd2-8da8-4b051c0a2275 -> ../../sda3
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 96231aa8-09d9-41e4-a40f-c428d87c9ab6 -> ../../sda2
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 b3df7655-a5a1-4a4b-bc9a-3c5dff81c24d -> ../../sda5
lrwxrwxrwx 1 root 0 10 Jul 29 06:22 b452250a-cdb2-41f5-92ac-0c7c736626f2 -> ../../sdc2
That's also what's contained in your bootloader config and kernel command line, so seems to be consistent at least:
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-server root=UUID=b3df7655-a5a1-4a4b-bc9a-3c5dff81c24d ro nokmsboot splash quiet resume=UUID=2844fbb9-df92-4d77-afde-efe101d42166 rd.debug
[ 0.000000] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-server root=UUID=b3df7655-a5a1-4a4b-bc9a-3c5dff81c24d ro nokmsboot splash quiet resume=UUID=2844fbb9-df92-4d77-afde-efe101d42166 rd.debug
[ 4.169151] dracut: ///lib/dracut/hooks/cmdline/10-parse-root-opts.sh@5(source): root=UUID=b3df7655-a5a1-4a4b-bc9a-3c5dff81c24d
So your question is actually the answer. Your system fails to mount this as it's being told to by bootloader (and probably fstab, so now also by the initrd)
because it tries to mount a partition that is actually part of the RAID device for /.