Modern shaft flex vs. Vintage

Would you say vintage shafts are more firm than today’s? Stiff then would be X-flex now…

Would Apex #4 compare to X100, or more like S300/S400?

My goal is to limit dispersion. The stiff irons in my Dynas are TT Stiff, but feel more stiff than my current S300’s… and the dispersion is better and the ball flight lower.