I honestly don't even get why reward pools are such a big deal.
I do work for you, I am owed compensation based on terms we've negotiated before I started working for you. From time to time these terms will come up for renegotiation.
There is no need for compensation in excess of what we've negotiated. Sure, I am not one to turn down free money, but understand that this does not affect our normal compensation discussions.
My work is worth $X on the market. I expect that you will pay me $X (or come up with alternative forms of compensation that are mutually agreeable). I will not sign a deal that adds up to $X where part of the compensation is discretionary. My work is worth what it's worth. If it is not up to your satisfaction, you are free to terminate this relationship or renegotiate my pay. You may not unilaterally decide to pay me less than what we agreed upon, and I will not submit to a system that allows this.
Which is to say, you will be unsuccessful if you try to persuade me to lower my base salary on the promise of "bonuses".
I feel that "bonuses" are just ways to hoodwink people who haven't been around the block. Every time I have come across bonuses of this variety, it has been an excuse to lower your base salary. I have never once received the full possible bonus, even though I have been promised multiple times prior to joining the company that "everyone" gets the full amount, and that only very poor performers don't. I have never received a poor performance review.
If you do not pay me $X, whether in salary or in bonuses or in suitcases of bacon, I will leave. I do not give one flying hoot about stack ranks, bonus pools, or any such nonsense. I am not willing to inject uncertainty into my income without a proportional upside for myself.
Discretionary bonuses are full of shit.