Without a doubt, Thanos is one of the most important Marvel villains and to his cunning, strength and evil, we must add an almost unstoppable army.
In both comics and movies, we have always seen Thanos accompanied by an army that practically seems infinite. Now we know the truth about this. Attention SPOILERS from the comic of Marvel Avengers Mech Strike # 4.
In this history, Thanos se a a the Avengers to be able to face Kang. In a moment of danger, he decides to send his army and that is when he explains where he gets so many followers willing to carry out any order and go to war.
When planning your attack, Black widow suggests a surprise attack to distract Kang, is when Thanos decides to sacrifice what he calls “Legions of space pirate scum”. When Spider-Man Asked why he is willing to send so many soldiers to their deaths, the Mad Titan comments that “the galaxy is full of bloodthirsty mobs, waiting for a powerful leader for whom to lay their lives “.
So we can intuit that Thanos he is not looking for people who follow his ideals or his cause. He simply influences followers with his power and with promises of great conquests.
The Avengers reject those methods.
Though heroes oppose how he does things, Thanos He shows that he does not care much about that, since he makes it clear that his army means nothing to him. Also in some other story like Thanos vol. 2 # 1, the great villain revealed that he has entire planets simply to house his soldiers. So it will always appear that you have almost infinite troops.
In the history of Marvel there are many great and very powerful leaders who demonstrate how Thanos that they have a knack for attracting people to fight for them. For example Magneto, who is always surrounded by mutants or Doctor Doom that it costs him next to nothing to gather scientists and soldiers.
The army of Thanos It will always be very numerous because it appeals to the worst feelings of all the beings that exist in the Universe. So you will never run out of people willing to do your dirty work.