Why combining German surface raiders could make them easier to catch

What if Germany's major battleships and pocket battleships had all conducted commerce raiding at the same time?

If they operated together, the slower Deutschland-class ships would make the group easier to catch, while Britain could concentrate more capital ships and carriers against it.

A simultaneous sortie by Germany's major surface raiders raises the problem of operating them together. If the faster capital ships stayed with the slower Deutschland-class ships, the combined force would be easier to hunt down. Britain could concentrate more capital ships and aircraft carriers against it than Germany could deploy. This conclusion depends on the raiders remaining together; it does not establish the same result for several independent sorties.