I'm fine with being more persnickety about the other options; they are much rarer and not unixy.
However, there's a complication: ... This remaining discrepancy might be okay, but I was really hoping to reduce the burden on users to figure out the correct ordering of options. The situations in which I've had to use single-user mode are precisely the situations in which I'd rather not have to spend time learning these kinds of details.
Yes, that's unfortunate. But I'd be okay with the db-last requirement as long as the error message is sane and points one in the right direction.