Conventional, dovetail, chopperlump & shoe lump all normally have their breeches joined by brazing. Dovetail chopperlump & monoblock breeches can be, & normally are, joined by soft solder. This was the big selling point of these methods, that the heat required for brazing was not required.
All methods are a comprise on some points, the major one for "Either" style of chopperlump is the lumps are by necessity made of the exact same mat'l as the bbl's. In most other methods the lumps are made of a harder steel.
