If they're incapable of holding realistic employment, and it's all down to you, then you're in a worse situation than being single.
Possible requirements, from best to worst:
(A has job) || (B has job) // Robustness!
(A has job) // B won't have job, but A's is enough.
(A has job) && (B has job) // Cost of living is more than max(A, B) and less than A + B.
If they're incapable of holding realistic employment, and it's all down to you, then you're in a worse situation than being single.
Possible requirements, from best to worst:
(A has job) || (B has job) // Robustness!
(A has job) // B won't have job, but A's is enough.
(A has job) && (B has job) // Cost of living is more than max(A, B) and less than A + B.