(Connexx 9.6.6/AMFit9.6.10) for A&M Newer/Current works separately from (Connexx 9.11.10/SiFit9.11.10) for Signia Newer/Current.
You can install both and run each one separately.
Though, that is not the way Connexx Legacy works. If you want to use two versions of Connexx Legacy here's a clip from a DIY School Hearing Aids PDF File named (01 Free Hearing Aid Fitting Software);
If you want to use both versions of Legacy/Connexx (Siemens/Signia and Rexton), install both versions. When the installation is complete, you will have two HI databases and one Legacy/Connexx6 executable. You can select which HI database you want to use from the Manufacturer drop-down menu and then select Siemens or Rexton; however, for new/current versions of Connexx, you will have two HI databases and two separate Connexx executables.
Also, A&M hearing aids are ReBranded hearing aids. You can read about those in a DIY School Hearing Aids (v2.2) PDF File named (Unlocking ReBranded Hearing Aids);