This was the type of short-term, below market type of extension I had mentioned before.
I'd think it's fair to assume he's going to get around $10 million this winter if he goes to arbitration. I'd also think it's fair to assume he's got another 3-4 two win seasons left. If you could get him to take a 3 year/$30 million deal with a team option for $10 million in 2025 I'd think that should turn out to be a relative "bargain" if he stays healthy.
Is that more than you'd like to pay? Sure - but I think there's a chance that that kind of deal could turn out to be really good, and not a whole lot of chance that it comes back to really bite you in the *ss if he stays healthy. There are always going to be folks who wind up disappointed in him since they expected him to be a star based on his draft position, but if you could lock down that position for the rest of your window for less money than Simmons is making at 31 years old that's a pretty good investment IMO. $10 million/year would put him somewhere in the range of the 12-15th highest-paid SS, and that's probably right where he ought to be (regardless of where the $/WAR number falls).