Thanks Mark , that is very helpful.
I am assuming ASL does 2 things , 1 prevents people getting in and 2 if they do get in some known vulnerabilities have been removed.
Juggernaut on the other hand , just prevents them getting in.
With that in mind , is Juggernaut enough for me and my 100 domains on Plesk , or should I stick with ASL , which I find quite complicated sometimes.