I read it as dowy suggesting a single relay team for each club, in which the separate legs were run by a runner (or pair of runners?) from each age category - that might work...?
Name a club that could find
1xU8
1xU10
1xU12
1xU14
and 1x U16 or U18
That's what Felljunior and I have been saying - there aren't any.