Union is strength or Unity is strength or Unity is power

[love-you-mom]

If people join together, they are more powerful
than if they work by themselves

Which one you prefer for this meaning ?

1- Union is strength
2- Unity is strength
3- Unity is power

 

[Tdol]

#2 is commonly used.

 

[konungursvia]

I like number two too.

 

[love-you-mom]

Number2
I like it too.

Thanks.

 

[sh3000]

Why?What's the difference between #2 and #3?