Signing of a doc by several signatories in any order, but only after approval by Approver(s)

I want several people to sign a document but only after a (or two) person(s) has approved the document. My experience is that this only works in a specified order, i.e.

1 - Approver approves

2 - Signatory 1 signs

3 - Signatory 2 signs

4 - Signatory 3 signs

and so on.

However I want that the Signatories can sign the document in any order after approval by the Approver, i.e.

1 - Approver approves

2 - Signatories 1, 2, 3,... sign in any order

Is that possible?