"Gotta wonder how many dairy animals are raised on recipient beef cows."
Not many.
Now, the opposite was, at one time, very common - and I'm convinced that a lot of beef herds introduced Johne's Disease to their herds/premises by buying Holstein heifers and cull Holstein cows to use as embryo recips back in the early days of Embryo Transfer.
Those de Lidia cattle - the Spanish/Portuguese fighting cattle - are selectively bred for their aggressiveness. Even the heifers are tested... "In the case of females, animals of 1, 2, or 3 years are evaluated. The test is practiced in the tienta, under the direction of the farmer and with the participation of professional bullfighters, trying to discover the functional performance of each animal. The behavior of each individual in each phase of the test is assessed using the horse and with the muleta. There are different parameters (prompt response, attack, fixity, mobility, nobility, fierceness, aggressiveness, repetition, and so on) that are evaluated by the farmer, to achieve a final note for each animal and, subsequently, keep the best females as breeders."
As the the OP's Angus/Hereford cross hand-reared bull that started this discussion on aggressive bulls, with forays into dairy, fighting cattle, and horses/llamas... I wouldn't trust that sucker for a second, regardless of breed makeup.
I've had several bottle-raised heifers that stayed in the beef herd, with a couple remaining 'tame' enough that you could walk up to them anywhere and rub them or put kids on their backs for a photo op... had one little Simbrah-cross cow that I could have milked, just standing in the pasture, if I'd wanted to. But... we had a Limousin heifer that we sold at about 6 months because she was far too aggressive to have around with my kids (7, 5, & 2)toddling around.