Yes. Add several numbers and Email2Phone dials them either one after another or all at once. That is an account-level setting under Configuration, and it applies to every call.
A second setting decides what happens once somebody acknowledges: stop there, or carry on until every number has been called. Stop-at-first is the usual choice for an on-call pair; carry-on is for the announcement case, where everyone should hear the same message.
Voicemail pickup counts as accepted for that setting (it is not an acknowledgement; only a keypress is). In stop-at-first mode, a number whose voicemail takes the message ends the sequence and the next number is not rung, so every number in a sequential list that has to wake someone should have voicemail off. In carry-on mode every number rings regardless.
Which numbers ring for a given email is decided by filters: each filter ticks the phones it should call, and anything no filter catches rings the default number. So the same account can ring one person for CRITICAL and three people for a site-wide notice.
This is dialling behaviour, not an on-call platform. There are no rotations, no who-is-primary-this-week and no handover; two or three numbers, a dialling order and a rule about when to stop. Each number can have its own quiet hours, which is what makes a desk-phone-by-day, mobile-by-night pair work.