I see 7 types all called Error within the same codebase. Is this acceptable?
My instinct says that having types with the same name in different domain contexts is OK, but it makes ambiguities increasingly likely when dealing with the “mother solution”.
The idea of namespaces is to allow this, and in many situations, it is ok. On the other hand, it makes some things harder
global search for all places of a specific type may suffer from getting too many results
moving one of those types to a more top-level component for wider re-use may be harder.
At all, IMHO it is not a all-or-nothing decision. Every time you choose a name for a type already there in another namespace, you should reconsider for a second or two if there may be not a better name, avoiding this.