Oh I took your first sentence to be that safe’s security is weak.
I am not the best person to answer this as I would have to read the whole wiki article to know what they are saying. My overview thought is that its a blockchain and and safe is different. Sharding for them is different to safe’s section mechanism.
Sharding will reduce their security, I agree.
They have no mathematical proofs for their sharding methods and as such can only have full confidence by selecting the best method and trying it for a period of time.
But again as to specific methods I cannot intelligently comment so sorry have to leave it there and maybe someone else can help here.