Link multiple websites from PBN make them weaker?

I read that if I use a PBN to link out multiple websites then for each outbound links the power is decreaded, but is it true?
I collaborated with a seo agency few times ago and I remember they didn't give a fuck about this, they put up to 10-12 outbound links to client websites for each PBN domain homepage... And the client websites actually ranked very well...

That is true - the fewer OBL - the more stronger each of them is. But links to other relevant websites from PBN is absolutely necessary to camouflage link to Money site and make it more natural for algorithms of Google (so there will be no manual review because 99 % of PBN will die after 10 seconds of manual revision)