As many other people have said here, I do not encounter such issues myself when starting up ARMA 3.
Startup time for me takes at least 1 minute minimum to 3 minutes if I'm running a bit slow. And in fact, when I have other programs running when I boot up ARMA 3, the programs actually slow down ARMA, rather than your case, causing me to alt-tab out and shut down all unnecessary programs.
Sorry to say, my only idea on how to fix this is to clean up your computer a bit and recheck your specs.