When the market is smaller, there are more room for error or mispriced lines.
This has been happening and I don't think it is only in low profile leagues, it does happen with big leagues. I recall there was a time it happened years back in Scottish premier league involving rangers, can't remember the other time now. When it was realized, it was immediately pulled down because rangers got a higher odd against lower team. Rangers later won the match as expected and it was big cash out for those who took the opportunity.
It is true that it could have a very rampant occurrence in lower leagues because bookmarkers might make mistakes more there than they would with popular top leagues.
But I don't know this occurrence as value bet and I have not seen bettors call it that name. What I know is that such happens and it will not be intentional because bookmarkers won't give out free money like that. I believe it is a mistake on their part and it is understandable that they may use wrong analysis to determine such odd as they are not top flight teams.