Absolutely, plus cache is not a binary network wide on/off as you have also seen. So caching will happen exponentially faster towards a reader, so the readers would need to be very dispersed on the network.
So we need to imagine the network as millions of networks (equal to number of data element plus nodes). These networks all share / overlap in multi directional ways. So a huge venn diagram. Caching happens fast close to origin of chunks and slower further away. So there is a pretty big balance of caching due to this. so a group of nodes near each other will cache fast, but nodes in a different direction will not (yet) have created cache copies.
Measurement of this will be very interesting, all I mean here is cache does not mean network wide on every path and this is confusing to some people, botnets will see cache fast though 