The larger the driver, the earlier in the frequencies the driver will have a natural rolloff because of beaming. It's entirely size dependant and not up for debate. 6.5" drivers start to "beam" at around 1.6khz, but not significantly until 2.5khz or so. If your speakers were pointed straight at your face, you might get some interference with frequency overlap at tweeter frequencies. Off axis, this is not likely to be a problem.
As an example... here is my 6.5's in my doors playing full range. The spike you DO see over 2.5khz is just "noise" and was there before I started the test. You can see how little information there is. This is because of beaming.
So, as you can see... you likely don't have to worry about the frequency overlap.