Why frequency alone is the wrong question
Since each post is ranked mostly on how the people who see it first respond, posting more often does not buy more reach. It creates more chances to earn engagement, and more chances to fail to. A higher volume of content nobody reacts to does not outperform a smaller volume that consistently earns real engagement.
What a reasonable baseline looks like
A Page posting a few times a week, consistently, strikes a workable balance: frequent enough that followers see it show up regularly, without stretching a small team past what it can sustain with worthwhile content.
Let engagement, not a calendar rule, set the real pace
If a given posting frequency is producing genuine engagement (comments, shares, private sends) the current pace is working. If engagement per post declines as frequency increases, that is a more reliable signal to slow down than any generic "post X times a week" rule.