You might enjoy reading this review article:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5415597/Among the conclusions: there does appear to be data supporting the contention that digits backwards has some connection to spatial span.
The skills themselves may have some relationship to executive functions, in addition to motor sequencing.
Implications for you specifically are more difficult to discern, as not much can be predicted from isolated scores. Also, what you describe as verbal short term memory may or may not actually be principally verbal in nature, depending on the exact task. If you'd like to discuss your profile, it would be more likely to be meaningful with more specific data (including which tests they were).
