Should I collect Tau or Necrons in Warhammer 40k?

Based on the fact that each force is organized using the points system, in theory two forces of equal points should be a fair match-up. The problem is the new rule set. Since Warhammer 40K has gone to 5th edition, the Necron codex hasn't been updated to match - so many of their strengths are lessened somewhat.

They're still a very strong army model for model, and much more forgiving on new players, so in that respect I think you'd do well with them. They're also quite easy to paint, which is a plus. On the other hand, because of the lack of variety in the models, they can get a bit... monotonous.

The Tau are definitely a different playstyle, and might take some getting used to - they have outstanding ranged weaponry, but against two armies that like to get up close and personal in assault, you might have issues. My brother uses Tau, and I really ruined his day a few times with my assault army of Orks. As far as your friend's army choices, I don't have much experience against Chaos ... more.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.