Welcome to our Pond Forum,
What is your closest town in Mid-MI? I went to graduate school at CMU with an excellent education in aquatic biology that has served me very well as a lifetime career.

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If you had any water puddle in the pond while the contractor was redoing the pond then you almost 100% have some sort old resident fish in the pond to reproduce next spring. It only takes 2 to get a troublesome population started.

Fish in your 1st post were a specie of true minnow -- maybe FHM and then even resembled bluntnose(BNM); pics were not good enough for me to make an ID?? Any Fish big enough to avoid a 2" pump evaded the pump suction. A 'Gee' brand bare wire mesh minnow trap sprayed a dark color, baited with bread or pet food, fished in shallow water parallel to shore in spring, should catch a fairly good representative sample of existing fish species, but no guarantee of all species present. Get some good close side pic of your catch in any. The trap might not be very successful due to only several fish or residual population of fish being present due to pond draining and dirt rework. The minnow trap can be always used to catch some native minnows in your area creeks or a small closest lake that would/could enhance your FHM stockings. The trap can also be useful for monitoring new YOY offspring fish (youngofyear). Note LMB will not or rarely ever enter a fish trap, fingerling SMB will enter traps. I can help with minnow identification before adding anything native. Be cautious of adding wild crayfish as you could be adding rusty crayfish(RC) that are invading MI waters and considered exotic and invasive with +and- features. Although RC are an okay but not great food for SMB and larger YP.

Starting with a "shallow muck hole" depending on starting depth, may have lent itself to winter fish kills where all the sport fish died. HOWEVER fish winterkills first kills the largest fish and small sized species OFTEN survive but not always.

Depending on location in MI there are two popular fish farms in your region.
Laggis Fish Farm Gobles MI. He has high quality fish. A two hr trip to his farm is worthwhile for good fish. His perch(YP) are premium stock from domesticated pellet raised fish. He raises his own pellet trained SMB. Best fish are YP, SMB. Walleye(WE) , and pike (NP) are retailed from other growers. I don’t know much about the quality of his Hybrid Bluegill (HBG) as (BGXgreen sunfish). http://www.laggisfishfarm.com/2011%20Fish%20Stocking.htm

Imlay fish Farm/Hatchery 1442 N Summers Rd. Imlay City. 810-724-2155. Always call before going for fish to make sure what they have in stock.
They have bass, blue gill, crappie, trout, perch, walleye, pike, catfish and (more?). No website. You have to look them up on Facebook. See their posts for examples of available fish. Be cautious with fish from them. The say they have wild caught BG which could be very risky business for you. Wild BG could have mixed genetics from natural hybridization.

No one in MI that I know of sells pumpkinseed sunfish or HSB.

You can grow nice fish in a 1/2ac to 1 ac pond without pellet feeding however they will not grow as fast, nor as many of them if you don't pellet feed. Feeding does not have to be daily and can be only limited amounts 1-2 per week; however production will be appropriate to the feeding amount and will not be as bountiful with minimal feedings. See your private message