Significance of duplicate territories

Summary:

What is the business impact if I create duplicate territories(with the same dimensions)

Content (required):

I have setup the following territory hierarchy

T-A

T-B , Parent = T-A

T-C, Parent =T-A

T-C1, Parent = T-C

T-C2, Parent = T-C

Assume T-C, T-C1, and T-C2 has the same dimensions but different owners.

There are 20 accounts that match T-C, T-C1, and T-C2, But in T-C1, I have added 5 accounts under the exclusion, and in T-C2, I have added 7 accounts under the exclusion list. This is done so as the owner of T-C1 and T-C2 should only see their accounts (created by themselves).

So, with the above setup, what will be the impact? is this a valid setup/approach?