I typed the following comment, but the site had an error, so pasting it here about 30 minutes too late:
And to add onto that:
Those coatings (AlTiN, TiAlN, etc) require heat to work better. The coefficient of friction is actually lower when they are a couple hundred degrees C, Which is pretty easy to do.
If the endmill isn't glowing or throwing a lot of sparks, it is fine.
And using coolant with a tool that is getting that hot is a recipe for premature wear, as it will thermally shock the tool as it gets hot and cold.
Tom often doesn't really read into the point of most questions. He has some valid info sometimes, but 95% of what he copied and pasted from his notes don't apply here.
To the OP: it seems you are just using conventional toolpaths? Just hogging along? That tool life seems okay. I will say that if you were using CAM using some adaptive/high speed milling toolpaths, you might get better life going much faster with smaller stepover. There is a bit of a learning curve in doing it but a lot of us use them almost exclusively to rough nowadays.
And just to add another question: are the tools you mention coated or uncoated? And are they variable flute/helix endmills? Both of these can improve your cutting situation.