Phazotron N019 of MiG-29A uses modified (read: upgraded) twist cassegrain antenna of a Saphir-23ML. It's a very logical decision since overall MiG-29 development prolonged and MiG had to "push it out". On the other side, size of Fulcum and Flogger radome are similar so it was a poor man's fortune.
On the other side NIIP Tihomirov tried to develop N001 radar so that it would outperform F-15 radars of that time (probably -63) with search range ~200km. They also tried to include the use of R-33 missiles. It was overly ambitious and they failed to achieve this. By that time ('82/'83) MiG-29 already began it's operational service in mainland CCCP so usage of N019 components was chosen. It was decided to use TS100 processor with a larger diameter version of N019 antenna.
However, the average transmitted power of 1kW is the same with both N019 and N001.
So about differentiating signals, let's say we've got two MiG-29A in the same space/same distance/same aspect. One of them has a fully functional or a brand new radar that emitts 1kW of power and his wingman flicks a radar that had more than 200 hours of usage and is uncapable of transmitting more than 300W...
Do you think your average TEWS would indicate a 29 and 21 flying at you?
edit:
or two 29 icons but the one with functional radar being a bigger threat?