[SEO] How tightly (related keywords) is tight enough?

Without wasting time...
I have 3 topics/groups of keywords, which are in the same niche, lets say, video games.

Let's assume the keyword groups are:
1) assassins creed (and related keywords)
2) world of warcraft (and related keywords)
3) prince of persia (and related keywords)

Now should I create separate sites for each of the above to: keep them tightly keyword focused and spread the risk of a penalty...

OR...

Should I create one single site with silo/categories for each video game and their related posts?


Q: Which one will help shield penalties? (lets face it, it's seo, every site IS going to be penalized sooner or later) Will the single, big authority site be more stable from google's animals or is it safer to keep them separate?

Q: Which structure would be more easy to rank? (Of course, "quality links" and the other yada yada being constant)


The dilemma is between easy, stable rankings with a big site versus keeping sites separate and shielding them from penalties.
Which one would be the lesser evil?

UPDATE:
Asking a related question instead of starting a new thread...
Q: Would it be wiser/too paranoid to keep all them sites separate in terms of g+ authorship, hosting, wp themes, etc... or am I being too paranoid? Has anyone experienced a kick on all sites from G when they kept the same host/themes/authorship and one of the sites get penalized?
(Assuming: None of the sites are linking each other or have any common links except MAYBE the social ones)

Would also like to know this answer !

No one with any experience?

I usually opt for 1 single site and build authority! Why would you get penalised if you go about it the right way? Just create 3 different pages on your site so that you can target each of your keywords. Spend time creating quality content, make sure it is better than your competitors and then get your on page SEO right!

This is a safer way of doing it rather than separate sites that probably won't have much meat to them. If for some reason you get penalised then de index the site and move the content to separate sites!

Hope this helps

Hey,
Thanks for your input... but do note that I don't have JUST 3 KEYWORDS... its more like "group of keywords"...

So ideally, I am going to be having 30-40 keyword posts on that 1 topic, and so on...

So technically, its not going to be a very shallow site each, about 50 pages on a site.
But if I go with your way, sure the total site content would go over 150 posts, but I am still scared for penalties.

Like you say, why worry, but if you see the SEO scenario, very few sites stand the test of time...

For that I guess you should focus on separate site and its proper SEO.