Programming advice
I've been scanning some 41 years. Been scanning these trunked systems since 2000.
I've tried it both ways, and my advice is to not use multi-site trunking. I think the best way to program your scanner is by area. Usually, this means by county, but a county like Salt Lake has so much activity, that I have to break it up. This is how I do it:
Every scanlist has the common TGRPs: LZ1, LZ2, Events, Regionals.
Scanlist 1 is SL Sheriff & UHP, and the local Fire TGs. SL Simul is the site.
Scanlist 2 is SL City TGRPs, AC33 is the site. I also have UHP on SL Simul site
Scanlist 3 has all the other jurisdictions in SL County: S Salt Lake, W Valley, etc.
Scanlist 4 covers Davis County. Davis Simul is the site.
Scanlist 5 covers Hill AFB, using their site
Scanlist 6 covers Weber County, Weber Simul is the site.
Scanlist 7 covers Box Elder County, mostly conventional
Scanlist 8 covers Tooele and Summit/Wasatch counties. Lots of sites.
Scanlist 9 covers Utah county, Utah Co Simul is the site.
When I travel to Evanston or Wendover, I have every site along the way. The scanner locks onto the strongest (Usually closest) site. When terrain blocks the signal, the scanner seeks a new control channel. This works well for the I-80 corridor.
If you try this from Davis County, your scanner may lock onto SL Simul, and when you want to hear the action at something like the Silver Eagle Refinery, you won't hear a thing because the scanner is listening "Out of county"