Missionshooter,

Most water will only support 75 to 125 lbs of crappie. So that 125 lbs probably constitutes the worst case. A 4.5" weighs .5 oz and so the maybe there are 4000 crappie/acre or 6000 in your pond. They will not produce offspring until you are able to reduce their numbers to where they are attaining 8" in length and so what you are dealing with is a limited number of them.

It takes a decent sized LMB to take 5" crappie but a 12"incher may be able to do it if you help by scissoring the dorsal fins and caudal fin. So catching and crippling may work with LMB around 12" in length until they get up in size. Those 5" crappie are definitely on the menu for LMB > 18" where is about where you need them. You need around 25 to 35 lbs per acre of 18" LMB to handle the dink crappie. Stocking fingerling LMB will end up giving the dink crappie snacks.

When you get them to 8", I would recommend harvesting crappie 8" or longer. They are big enough to eat and this will allow you to grow some larger specimens.

An easier approach may be to try one 20 lb flathead until you get the crappie up to 8" at which time you could harvest the flathead and add some bass in advanced fingerling sizes > 8" about 50/acre. Try to do that transition in fall.