How to setup two wireless Sennheiser G3 transmitters with one receiver ?

[AAC]

I've been using Sennheiser G3 clips-on and plug-on set on my Panasonic AGAC160 for two years. I know that the G3 receiver is only to pick up audio signal from either clips-on microphone or plug-on transmitter. This Summer, I will have more more symposium to tape. I need to record two people's conversation on stage. Ideally, each of them will have clips-on microphones and signal be picked up by G3's receiver on camcorder. There is no audio mixer in the symposium.
Sennheiser people suggested me to get another set of G3 and connecting two receivers on camcorder's audio input 1 & 2 to pick up transmitter 1 and 2. I don't think this is a good solution. Do I need 3 sets of G3 if there is third speaker ? There are only two XLR inputs on AG-AC 160.

Appreciate all suggestions from experts, or I may consider other brand that support multi transmitters if you guys suggest.

[Cornucopia]

Wireless transceivers work when they can isolate and lock onto the appropriate carrier frequency amidst other other conflicting signals (including noise).

If you attempt to simultaneously piggyback 2 signals on the same carrier, it cannot isolate and lock. One or the other of the 2 signals will look like noise to the receiver.

Sennheiser guys were right. You need 2 transmitters and 2 corresponding receivers (3 pairs if you need 3 signals, etc). If you only have 2 input channels but more than 2 signals, you will need a mixer also.

Scott