It's worth keeping in mind that crew requirements are primarily a function of each navy's operating practices, not a function of technology.
The more we learn about the Mogamis, the more apparent it is that there is no "secret sauce" around manning that the Japanese somehow magically discovered. What's really happening (as far as I can tell) is that the JMSDF cut crew numbers by accepting compromises in several key warfighting areas that would be unacceptable to other navies, starting with cuts to damage control and maintenance teams. They've also eliminated at-sea training by eliminating junior crew positions (which is how many navies handle career paths, by on-the-job apprenticeship).
There is nothing new here (IMHO) that hasn't already been tried in the last 20 years elsewhere, e.g. USN (LCS) and the RSN (Formidable class), with mixed success.
While Singapore certainly seems to be happy operating their frigates with core crews of only 71, it's worth noting that when the French Navy tried to do the same with basically the same technology in their FREMM frigates (built by the same yard), they quickly found that they had to increase core crews from 94 to 109 to reduce fatigue during longer stints at sea. And even that wasn't enough for "combat" deployments... so now following a decade of operational experience they are increasing their frigate core crews (again) to 131-144 sailors... TWICE Singapore's baseline, and 40-50% over their initial starting point for the FREMMs.
So it all comes down to watchkeeping practices (are you preparing for 4-6 month long combat deployments to the Red Sea or just patrolling home waters?), maintenance & damage control practices, how many boarding teams you need, whether you want junior crew members to learn only ashore or by being embedded inside an operational crew etc. To illustrate with some numbers, a FREMM's combat operations team is 70-80 sailors. That's what's considered necessary to maintain permanent 24/7 watches in all warfare areas for 30+ days at sea. Then you have a "platform" crew of ~30 sailors to handle engineering, damage control watches, as well as ongoing maintenance. Finally you also need ~30 sailors to support the crew (everything from cooks to admin to boarding teams).
You can of course cut all that. Fewer cooks & admin, no dedicated boarding teams, no dedicated damage control watch or ongoing maintenance. Cut watchstanders from 3 watches to 2 watches. Skimp on your SIGINT and sonar watch - maybe let a computer do the job for you. Eliminate dedicated weapons crews who would reload guns and decoys in the middle of a firefight. No doctor on board, no one to handle logistics during foreign port calls or to manage spare parts, no secretary to handle administrative duties. No problem, core crew is now well under 100! Good luck maintaining combat readiness during a 4-6 month deployment to the Red Sea or South China Sea...