Is it normal for a guy to be afraid of big men?

Men are hard wired to notice other men who could kill them because they need to be careful, size is a masculine positive in every dimension men are big and strong the bigger and stronger the more deadly you face up to a genetically more gifted man then you and your biology tells you this is a dangerous situation. Genetics man it's a lottery and unless you're massive you'll encounter lots of men who are bigger than you all about understanding yourself in those uncomfortable moments when you feel small and remember that size no longer defines a man as we live in society its evolutionary back log it's not super relevant anymore though when it comes to attracting girls it is very relevant

Normal but you’re a pussy. A scared guy isn’t attractive to women and can come across as feminine/submissive.

1905 millimeters

Little guys seem to be less nervous around me than the bigger ones because everyone is big to them.

No. In fact, I recommend pricking their skin with a needle to overcome that fear.

I think that's just common sense survival wise.

In males seeing a physically superior man or someone who is taller thus having a reach advantage just shows were we are on the "if we fought to the death how would it go for me" chart.

I dont get intimidated by big dudes because 1) I tend to talk my way out of problems 2) I fight very brutally 3) theres some mild levels of self delusion on my real chances in a fight.

Yes it is.