Sounds to me like you did everything right other than your protein extraction.
Beef vs. Pork does not matter and neither will the fat ratios. Spice selection makes no difference either, some spices may need more mixing than others to get the right extraction.
Just for argument sake and as an example:
Not that you should but you could add 4-6 cups of water and with enough mixing and protein extraction make that mix so stiff that you would struggle to crank it out. On the flip side you could use no water at all, spice the meat, hand mix for a minute or less which would give you virtually no protein extraction and that mix would crank out with virtually no effort.
Next time you get things dirty do an experiment to help get a feel for protein extraction:
Getting the right protein extraction is not something you can get with a clock it is a feel, I know by the sound the meat makes during mixing when it is done mixing and ready for the stuffer but that comes from many years (and pounds)of experience, you can get the same thing by feel so pay close attention to how it looks and feels in your hands when mixing/stuffing.
Pull a pound or two out at the start of mixing as soon as the spice is mixed in, stuff, link, and set aside. Half way through your anticipated mixing time do the same thing. And then finally at the end finish stuffing the rest. Pay close attention to how the meat looks, feels, stuffs, and links for all 3 versions.
Next time you have friends/family over grill some up making sure to keep all 3 version separate. Cut them up on separate plates and have your guests try all 3 and pick which they prefer. It’s going to come down to how you and your family like them but getting thoughts and opinions from as many people as possible is part of the learning.