A couple of things you need to keep in mind. T/S parameters are not constant. They do change based on the temperature among other things. Interestingly enough, even if you test the T/S and they differ, you can try to simulate it, and more often than not (with a good company) the results in winisd will be similar. I did a video a while ago about Do I need to break in a sub? It is found here:
For the most part, companies like Dayton, I have found their t/s parameters to match their winISD simulation. For the tweeters, they are relatively similar. They aren’t going to be identical, as they aren’t matched pairs. How the the response look? My guess is the minor differences you are seeing will not affect the response. But if it does, absolutely return them.
As for the Z offset, you could mount them on the baffle. Just know that you will not be able to create the crossover from that. You will want the drivers in the box to properly account for baffle step.
