How many meats can make a meatball? So I want make a Swedish meatball style meatloaf. When I make Swedish meatballs I usually use veal and ground pork, but I've always wanted to throw in some ground lamb and buffalo.

So the specific question here is for a meatball how many of these meats can I get away with including in these balls
Of juicy meat?

And more generally, what are the guiding principles in combing meats from
Different animals like this? Hoping there's like a periodic table of savory sensations I can put on the kitchen wall, but any anecdotal suggestions will be sufficient.
You should be able to combine as many as you want.  Pay attention to the fat content in each meat, as that can make a big difference in the yield as well as the texture.  However, even if you make a fairly significant change (for example, from 20% fat to 10% fat), it still won't be wrong or inedible, just different.  (Although, I wouldn't recommend trying anything insane like 95% fat.  It's no longer a meatball/meatloaf at that point.)

The meatballs I regularly make were derived from a Swedish meatball recipe.  I use 100% ground beef instead of the other meats, and it works really well.  Also, instead of the traditional Swedish meatball sauce, I use marinara sauce.  It's delicious!