Got an answer on another forum. Just adding this to let it drop down. George

Well, ted, that would all depend upon where you live! Although Arabian Night could normally be bought here, I don't recall seeing Bristol Stripe or Tahiti Sunrise here. And I know I haven't seen Myrtle's Folly, because I would snatch it up in a second. Now that I pretty much know which of my tubers did or didn't survive, I checked our local grower's website...he's all sold out...of everything. And I've been looking at the local stores and there hasn't been much of anything this year, except mixed packages of unnamed tubers. If I had decent looking tubers that I hadn't planted yet, I'd trade.

Coincidentally, my grocery store also had their display up today, and today was my monthly shopping trip (COVID has changed the way I do things a lot). I walked out with five new dahlia. I'll find homes. The freesia and ranunculus I picked up...there's always a home for everything. Somewhere. I start my old dahlia and new in pots every year, about four weeks before the "absolute guarantee end of frost" to give them a head start. It works great. With so little time in pots, I just give them whatever's on-hand and whatever soil I have left-over by that time. Average last frost for me is April 20th, but I won't plant the dahlia until May 1st at the earliest in the most protected parts of the beds, and May 10th in most of the rest for warmer soil. As noted, just lop off anything broken or nasty looking. Damp the soil, you don't need to soak it. And be patient. Some are morning-birds and shoot out in days. Some will take a while. Taller dahlia do benefit from being staked or, if you're lazy like I am, being planted in tomato cages. Shorter ones don't care. Not recommended but if you have to...: Don't push it too far and keep an eye on the soil and air temperatures. https://www.greencastonline.com/tools/soil-temperature You can cheat a little bit by using a sunny southern bed with a dahlia--the "formal" soil temp may not be quite sixty, but the temperature there will be, and an already-sprouted dahlia won't stop growing just because it's a little chilly (these are my "May 1" planted dahlia). Been there, done that, got the T-shirt. They'll slow, stall, and wait, but they won't die unless temperatures fall to frost. Consequently, my mailbox dahlia tends to be a bit late and slow, but since it was already 2' tall when I planted it, OK (my May 10 dahlia--soil's still a little cool, but not too far off by then).

see if any of these might help: https://duckduckgo.com/?t=ffnt&q=dividing+dahlia+tubers&iax=videos&ia=videos and why is it important to you that they have less sprouts??? the tuber is a storage unit for dormancy and once new growth starts.. one would hope it would put down roots to feed the new growth .. and eventually store energy for next dormancy ... one would think that it wouldnt be relying on said stored energy for very long .. as once the leaves emerge.. and start processing sunlight into energy.. the plant wont be using the stored energy .. the only reason i could see to limit sprouts.. would be if you were a hardcore grower who plans on entering flower shows and your goal is one single perfect flower .. and if you were doing that.. i would think you would have years of experience .. and would know the answer all that said.. you seem to have multiples .. so make notes.. and experiment on different plants .. and see what happens.. many of us.. didnt have the WWw to confuse us .. lol.. and we just did a lot of experimenting ... and that was part of the fun .. and frankly.. i remember my experiments more than anything i ever read ... good luck and have fun ken