I have very, very short legs, and an ordinary torso. I am 73, not in great health, and could use a better biike to do longer (20-30mile) rides than what I usually do.

The short legs always made bike fitting tough. I tried the smallest Allant 8S today.

My current bike has 22 inches from seatpost to stem. The smallest size Allant 8S is 23.4 inches. I can use a shorter stem, but the bike felt a little small. It was a very short ride, it could be I just need to get used to it.

Overall, it's a big improvement over my old Felt ebike. Felt never got the hang of making ebikes, and gave up.

The price is basically a grand off, so for the price of a $2500 ebike, you get the performance motor, good hydraulic brakes, a 625 watt battery.

There is also an 8S Stagger, but they didn't have one on the floor, and I don't know what the difference is between the 8S and the 8S Stagger.

Any help greatly appreciated.

For regular bikes I like the Diamond frame, for E bikes I would go with a low step or stagger frame for practical reasons. That extra weight makes its harder to tip the bike to throw a leg over with e bikes. I tried the Allant 7S plus with the diamond shape and it was just more easier to mount and dismount the bike with stagger.

Rivendell (and others) have swept back handlebars that could fix the seatpost to stem situation.

Allant is Trek's more sporty-themed commuter. The bar is lower and further forward.

If you like a closer or higher bar, you should be looking at the Verve line, which are also less expensive, by the way.

Did you use their "What is my Size" tool? They consider both height and inseam. It's in the right column, below the size selection here:
https://www.trekbikes.com/us/en_US/b...nt-8s/p/30265/

It says if you're shorter than 5'5" tall, you're out of luck.

It's a template website, so the Verve models will have their own.

Your local Trek store will probably also be able to get Reid eBikes, which are a bit different in design and are half the price of most Treks.

Electra cruisers are now owned by Trek as well and are particularly well-suited to shorter riders and those with bigger bellies that get in the way when hunched over. My wife's a shorty, and she has an Electra eBike; loves it, but you have to like that beach cruiser style.

Perhaps not relevant, but here goes anyway: I have converted several standard bikes - two hybrids, two tandems and a road/touring bike with kits, both hub drive and mid drive. All bikes have batteries mounted on luggage racks behind the rider. Yes, this gives the bikes potentially squirrely handling, but my wife and I ride only on paved surfaces at moderate speeds, so the top-heavy battery arrangement hasn't presented much of a problem. I will mention however that the bikes are prone to tipping over when parked, so we have to secure them to stationary objects whenever we dismount for any time.

I built a 48V, 1000w rear hub rigid MTB with a YESCOM kit that was operated at 52V (with its 30 amp controller more like 1500w) and positioned the battery inside the frame, in a front rack or a rear rack. Surprisingly (for me), the bike handled best with the motor in the rear rack.

An Allant 8s is a significant consideration. I imagine the test ride was conducted under the auspices of a dealer? Wouldn't they be in the best position to determine your fit on the bike? The diff between the 'stagger' model and standard is strictly in whether you like a 'step-through' or 'step over' style of bike. Someone with 'short legs' need not necessarily buy the smallest size available because 'reach' is still normal if upper body dimensions are typical. That maybe why the bike felt 'small'. It is. Maybe the Medium size is a better fit and with the seat at an appropriate height the bike will feel better.