It depends on how you use your radios and how many radios you have I think.
At home, where I have multiple radios... I tend not to really scan much. I know what I want to listen to and just keep the radios on those freqs or group of freqs. For example one radio might just listen to 3 channels because those 3 are very similar and only one might ever get traffic on it at a time, whereas another radio might only listen to one frequency and one frequency only because I never want to miss anything on that frequency.
When I'm away from home in a new area, I set up my handheld in 3 ways: Walking, Driving, Desktop.
With my 396xt, the first 10 banks are for driving and walking... where I can't really look down at the keypad, or fiddle with it much.
So for Phoenix arizona I have:
1 - Phx Fire A Deck (fire stuff)
2 - Phx Fire K Deck (medical/accidents stuff)
3 - Local PDs (the ones I'm most likely to encounter when driving)
4 - AZ DPS (highway patrol)
5- AZ DOT (dept of transportation)
these are my driving groups. On the road, I'll leave 123 on.. if I'm heading for freeways, i can flip it to 4 and 5, and not be bothered with taking my eyes off the road or anything.
6 is the entire Regional trunked system which has a ton of police, fire, public works, interop, and what not.... when I'm walking around and just need to listen/find something, it's gonna be in there. I don't have to memorize any numbers or anything. TG bank 1 is phx pd, 2 is other pd, 3 are their tactical chs, 4 is interop, 5 is the rail system, 6 is public works, 7 is fire. Easy peasy for when i'm out and about.
7 is all the other fire stuff nearby like USFS and BLM, Rural Metro, and other departments
8 is EMS like AMR and Medevac Helos
9 is MILAIR when I'm near Luke AFB
and 10 is USAF Luke trunk system
That way when I'm just out and about, I can easily find what I need in 6 through 10 with just some duplication in the fire and the rwc things.
For the rest, it's for when I'm using IDTracker to control my scanner. I use a touchscreen tablet as a 2nd monitor and put the systems over there. So all the things I want to listen to, get their own bank/key so I can easily activate them and turn them on and off and go to them quickly. If there is an incident, I can just select what channels I want, turn off what I don't want and it's all with a tap of the screen and no fumbling with function this and that and remembering what is where and what number it is.
I attached a screenshot so it might make more sense.
Yeah. there's a lot of duplication but at the same time, this allows me to use one radio 3 different ways and in a way that suits my need.
One thing I'd really recommend is ID'ing what you really want to listen to and keeping that in a "home" or special bank. Maybe separate the dispatch from the tactical to keep the chatter from overriding the callouts and vice versa, and figure out what you want to hear vs what doesn't matter to you.
I'll give you an example from Los Angeles.
CHP has a frequency, CHP Blue where they issue sigalerts, or traffic advisories, and they also put most of the pursuits there. It's a great channel to ALWAYS monitor.
LAPD has a traffic division frequency for a bureau, so when I'm driving, I listen to that, not each division because the Valley traffic division will put out all of the calls in the area that are important plus the accidents and stuff that matter for the whole area.
We have VFIRE21 which multiple cities will monitor and if there is a brush fire, they'll notify each other on there..... that's a bigtime MUST listen to.
See why keeping those freqs in a special group would be better than just leaving them in their traditional banks? Pick and choose what you really want to hear... and listen to that.. and leave the rest for when things are slow/boring or you feel like exploring.