Brother Adam & Buckfast.

[alanf]

This sort of thing?

carniolan
"....They swarm excessively. This trait could be put to very good use by a queen producer. Since they swarm a lot they are more inclined to produce lots of queen cells. Using these bees for cell starters and finishers would make it easier to rear more cells..." Carl A. Jurica, Practical Queen Production in the North

'More' suggests quantity rather than quality but it does suggest separate strains can be useful. Thanks for reference.