Hi,
All components of TestComplete's test project (except script units to certain extent) must be considered as binaries that do not support merging. This is the primary rule that one must always remember and keep in mind while designing a process for any version control system to be used with TestComplete.
The above means that the primary and probably only way that any version control system should be used with TestComplete is to provide backup functionality for test project.
With the above in mind, network share will work equally well as any version control system.