I'm not going to shit on what looks like someone's first paintjob (plus that freehand Star of David looks good and he's using based firstborn), but I am going to take the time to highlight how I see the best use of copy real-life identities/organizations into Warhammer.
If you are painting a 1:1 representation of an identity, make it look well painted. If someone wants to paint a space marine in the pride flag, make your freehand look steady and clean. Being able to do a rainbow color scheme is more impressive than making a political statement.
If you are trying to make an army that's Jews In Space or Native Americans In Space or Nazis In Space, don't just transplant the group into the 41st millennium. Not only is it narrative breaking, it's going to piss some people off, especially if you do something like make an Imperial Guard army with swastika arm bands. If you take a modern culture and transplant it 38,000 years into the future, evolve it. For this guy's army, either they have taken on the symbol of Judaism but have given it a 40k twist or they literally are the descendants of the Jewish people and if so give religion a more militant monk theme to it.
Otherwise just go ham with it, like the Catachans being a parody of American Vietnam War films. Have a detachment of allied Sisters of Battle to act as nagging Jewish mothers. Give the chaplains torah scrolls to read from (or for a bit of a sacrilegious tone, make their weapon a power torah). Make the Chapter Master Mel Brooks and the first company captain Larry David.
I guess that if you are going to take real world inspiration, make the army stand out.