Unfortunately segment definitions in a linear gauge mini chart have to be the same across all rows. I've spent some time myself trying to get segment definitions which dynamically adjust across rows but I'm pretty sure this can't be done.
Looks like it's been suggested as an idea...
I'd like to vote for the idea you linked but I'm not allowed to see that community area and I can't find it on area's list to ask to the owner to give me the access.
Have you any suggestion on how I could take the opportunity to vote?