Looks like we are talking about different DAG-coins. My version of DAG doesn't care about network topology.
We're definitely on different pages here. I don't know anything about this thing of yours.
Small world topology with 3 neighbors (this is enough to effectively propagate data) requires to send 3 times of that...
You're not going to be able to "effectively" propagate that transaction in 1 second to 7000 nodes with 3 neighbors. You would never have distributed consensus among those nodes. If user's can't get distributed consensus, then they will gravitate toward the subset of node(s) which has(have) the closest thing to it.
I don't see how DagCoin avoids this issue, and I stress that I'm talking about the DagCoin in this thread and not "a DAG coin" in general. Though I'm skeptical of the latter as well..