Our client has 2 websites, each on their own domain, let's call them
B.example, both interesting to the same demographic.
A.example is a small but very successful single purpose site with plenty of inbound links from the entire industry, including competitors to
B.example. It has virtually no competition itself and is the go-to source of its kind in the region.
B.example is a newcomer, both its scope as well as its actual size are much bigger. It has strong pre-existing competition. The owner of the two sites is thinking about merging them both under the
B.example domain, as either
B.example/A (while leaving a redirect on
A.example), basically to bring SEO benefits to
B.example (branding and everything else will also merge).
What would be more appropriate,
B.example/A? Are there any SEO dangers to this, would simply linking from
B.example be better? Or should we suggest the other way around,
B.A.example (though this could prove to be a hard sell to marketing, but as long as we're talking technically)?