I never said "all" of Blackrock and Vanguards holdings were solely via their ETFs. Did I? Did I even begin to insinuate that?
I can guarantee you that if someone had access to the granular holdings of the different ETFs operated by Blackrock\Vanguard that it would make up a super majority of their holdings.
IWM (iShares Russell 2000 ETF) owned by Blackrock holds 2.62M shares of LWLG and it makes up .03% of the ETF. Every Russell 2000 ETF that seeks to simply mirror the index will be similarly weighted.