If you were invaded by that many people, you very likely have invaded people yourself. Otherwise, it's very unlikely to get invaded. So then you sort of had it coming
Set up security and buy good guns/ max armour for your base
I deliberately kept my fob tiny but packed to the brim with bad soldiers with good equipment
Why would anyone attack a base full of d's who are armed to the teeth swarming the place when the only reward is 10 random soldiers instead of just scrolling down and attacking a base with a poorly defended strut packed to the brim with easy resources to steal
I put about 250 hours into MGSV (though a good portion of those were AFK resources generating). My FOB didn't get invaded one single time. Which actually disappointed me.
If you were invaded by that many people, you very likely have invaded people yourself. Otherwise, it's very unlikely to get invaded. So then you sort of had it coming
People(who have not played FOB) have exaggerated and scared people away from this part of the game. To not play the main game because of this is ridiculous.
Ways to avoid being attacked
1.) Do not build a Nuke. If you have a nuke you will be attacked immediately
2.) Do not develop you FOB. At this point most low level people do not really have anything worth while for invaders.
3.) Do not attack anybody else.
Also c'mon guys what are you really losing? You can protect your high ranking soldiers and stop them from being taken.