you can see here german tractor makers and their products, Bulldog is listed as part of make to differentiate it from Lanz Hela a different unrelated maker who also did tractors...
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BUT thinking about it maybe best solution, change all the Bulldog makes to model name , Alldog also model name
It is not very clear indeed, Bulldog seems to be a model range rather than really a separate make from other Lanz products. Maybe it is like the MGA or MGB, they are MG in the end even if the model name is often linked to the make name.
For now I left Lanz Bulldog as separate make, but maybe this could be changed some day.