What radar mode are you operating in? What tradeoffs have you made between pulse duration, duty ratio, scan speed? What tradeoffs have you made in antenna setup for sidelobe performance, ECM, etc? How far off-axis is the target? Have you got a swashplate design, or a fixed forward-only array? How sensitive are your receivers, how much loss is built into the system? How much does the aircraft nose cone distort the signal? How effective are your signal processing algorithms? How much processing power did you build into the signal and data processors to carry out those algorithms?
All of those factors can be applied equally to a 700 or 600 mm aperture radar. The larger one will always - assuming the same technology change is applied to each - have a range advantage.
It's like the engine size in a car at the end of the day. Yes a 1.6 turbo 16v can be more powerful than a 2.0 n/a 8v car. But implement turbocharging & a 16v head on the 2.0 and it will always have the potential to deliver more power.
The same applies to the radar aperture. I'd be interested to know if my 8% assumed basic benefit from the radar range equation for rafale vs typhoon is sound. I think it is a valid point as while you can play with/upgrade signal processing etc. it is, for practically purposes, impossible to alter the diameter of the airframe at the radome. Rafale will only have 600mm for 30+ years.