Those numbers you're looking at are for maximizing operations (cycle times, cutter life, surface finish, etc.), under ideal conditions, on much larger/more rigid machines. None of that has anything to do with hobby machining on much, much smaller machines.
When you are dealing with hobby level machines you are much better off listening to the machine/cutter/material interface during cutting. Your mill and/or cutter will tell you when they're happy, if you just listen and observe. This is why I don't install power feeds right away on a new mill. I want to turn the handles, and feel/hear what the mill is doing when it's cutting. This gives me a better idea of it's capabilities than flipping a switch and turning around to take a sip of coffee.
Each machine is different. Some are tighter than others, some are looser. Some are more rigid than others. Some have more power than others. Etc, etc..
So I needed to mill slots in a hardened piece of steel, using a 1/8" ball endmill. On a tiny Sherline mill. I had a honest to goodness machinist tell me it couldn't be done on that 'toy'. He was wrong.
Just a suggestion, but don't overthink this. Get your machine(s), get them set up, and experiment. And have some fun while you're at it.
