Hi Sacguy,
Yes smart move to get directly Voltera and Axxent expander modules with your Metron, makes sense!
Ha, ha, to me it sounds like for a while (after you receive the Metron + expanders + Eloquencer) you have enough sequencers for your racks :-) Now trying to bundle them together and let them all work together in harmony might be the largest challenge ;-) I have the same challenge with my trio of Drum Sequencer (Erica Synths), Vector and Sinfonion :-)
Let's hope that UPS delivery person doesn't get shot in down town Sacramento (but I guess and hope the shooting has stopped by now?) so you get your Metron by today ;-) Have fun later with the Metron and kind regards, Garfield.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads