Having ridden only my road bike, it’s hard to get my mind around some of the tire widths on these e-bikes I’ve been looking at. In theory I think I’d enjoy riding on hard packed trails with the more robust and wider tires. Also, having originally said that I don’t think I need a class 3 bike, now I’m intrigued by the possibility of riding beyond 20 mph. So I’ve been looking at the Allant +7S, and the Medeo T10+. Also the Vado 4.0.
This one can be a can of worms to some extent - tire compound(s), tread pattern, width, tire pressure, all have an effect, but also even the definition of 'hard-packed trails' changes from one person or location to another.
Some hard-packed trails are solid enough that even after downpours it's more or less easily passable on 'road tires,' but add a bit of clay, mud or standing water and it's a different story quickly. Reducing tire pressure a bit will improve things, but only to a point.
Went through literally decades of this on my various dual-spot motorcycles, and it's all about finding the right compromise. Knobby tires will hum and squirm on the street but grip much better off-road, especially once things get to not-so-hard-packed and loose, wet. etc. Wider rims/tires also tend to help vs narrower road-only setups in those cases.
Schwalbe has a set of values they give for rolling resistance (lower is generally faster for same effort on flat, perfect road, higher is usually gripper, wider, or more traction overall), road grip, off-road grip and durability... but as usual, anything like this is manufacturer specific, and you won't currently find anything claiming to be 'best' across all 4 categories. Example can be seen on the Johnny Watts:
https://www.schwalbetires.com/Johnny-Watts-365-11159377
Personally, I'm happy with the JWs as an 'all arounder' which I have on my personally built i35 wheelset, and on i40 rims previously, and am running in 27.5x2.8" width...which wouldn't fit width-wise on my wife's Medeo which still has the original 'Big Apple' (
https://www.schwalbetires.com/Big-Apple-11100426.01 ).
If you try to compare the two, the JW is clearly a 'dual-sport' type of tire, leaning a bit more towards the off-road side of things, while the Big Apple is more or less a road tire that can handle some small amount of light trail use, and of course on the Medeo os probably at least a half inch narrower. When it's time for tires on her bike, I'll probably look for something 'moving the needle towards the right' meaning a bit more trail-worthy, but not as knobby as the JWs. If you look at the JW, you can tell what makes it 'not dedicated off-road' - the knobs aren't super-deep, but also the center knobs almost form a solid line of rubber - this is what keeps them quiet(-ish, -er) on the road compared to full off-road focused knobbies, while the tread depth on the Big Apple is even much shallower, and the center treat is almost completely solid, and wider.
I'll probably look at something like the Marathon Plus for my wife's Medeo's next tire. You can see the difference in tire tread just glancing at Schwalbe's 'SUV e-bike tires' here:
https://www.schwalbetires.com/e-bike-tires/suv-e-bike-tires/
I think I take some minor issue with their 'SUV' nomenclature, as my carbon fiber X2 certainly isn't a big heavy pig - for an e-bike, but it's as good a grouping as any, as by definition any 'multi-use' type of tire (or vehicle) isn't likely to be the best at either one, but can with some patience and proper setup, certainly be 'pretty good' for more than one purpose (e.g. on-road/commuting vs some levels of off-road..).