You're right that compulsory annuities are a thing of the past.
Is the current one Defined Contribution? You only say contributory and Defined Benefit (like Final Salary) can be contributory - in fact, usually is these days I think. I'm guessing you mean Defined Contrubition though, as you're differentiating it.
If so, you can access a DC pension from age 55, so he can already access that if he retires early. He can take 25% of it tax free. Thereafter it's taxed according to his normal allowance. Think that's about £11K. So if he's not working at not drawing the FS pensions, he could drawdown from the DC up to £11K a year after the 25% before paying tax.
With regards to the FS - yes, it's 25% of each. Has he checked the scheme retirement age for them? As at least one is likely to have been set up before the change to SPA to 66, could well be available without actuarial reduction from 65, or maybe even earlier. Has he asked whether he can take them early with actuarial reduction? (often 4% per year taken earlier)
If I were him, I'd see an IFA and look at how quickly I could take the FSs, and whether the DC would bridge me until then.
In the meantime, start living on the equivalent pension income now, and save every penny above that - gets him retired sooner, and proves the income is OK!
Also have a look into his state pension forecast - with two FSs I expect he has contracted out of some years. So worth checking whether hanging on at work (or buying additional years) will make much difference.
What is your own pension situation? If you don't have one and you're a non tax payer, you can consider putting £2880 a year into a SIPP and having it increased to £3600 by the government. A nice little extra if you do it for a few years before he retires and has the money to do it.