"It is not necessary for the acts that constitute infringement to be performed by one person or entity. When infringement results from the participation and combined action(s) of more than one person or entity, they are all joint infringers and jointly liable for patent infringement."

"if separate companies work together to perform all the steps of a claim of a patent,"

Common sense to me, if, this relates to a linage of business relationships...i.e Vivitar and all related companies up stream from them.

Do all of the 7 companies served in the 2nd filing have a common connection up stream, where Vivitar might not?

doni