also {targets} token has only singular

No, with {targets} you can add a list contextual rule. You might have to set it up in your language administrator panel.

SOLVED!

Language Manager shall activate List Rules for your language at Language Management Page and all problems for "actors" and "targets" are solved.
Best example:
{targets} received gifts from {actors}
will give 4 different phrases:
actors contains one element and targets contains one element
actors contains one element and targets contains at least two elements
actors contains at least two elements and targets contains one element
actors contains at least two elements and targets contains at least two elements