This was what i was thinking, especially with the Sennies since they are 30mW transmitters IIRC.
Morsel of info: Senny gifted the world by upping G4's output options to 10/30/50 mW.
Their engineering philosophy seems to embrace lower TX power paired with more sensitive RX than the competition's. It appears that they achieve comparable function by having very good RX tracking filtering. Lower TX power inherently allows their cheapest combiners to have looser isolation and amplification specs while still generating tolerably low IMD products. Their fine "German engineering" certainly lives up to its reputation and results in a large $ to performance ratio.