You will be fine with the starline . We just answered , in our opinion, what we thought was the "best" 32/20 brass. By all means load and shoot the starline it is good brass , better than the Remington not quite as good as the Winchester. Will you be able to tell a difference in shooting it , probably not , will it last as long as the Winchester , well shoot it up and see how long it last . 32/20 brass by it's nature is fragile and you will ruin some loading it so just practice and get to know the round. Mine 10 32/20 is very accurate, more than my 10" 30 carbine and either will shoot better than I can hold off hand any more. I have had good luck with the speer plinker or Hornady 100 grain short jacket. You didn't mention what size animals you are shooting. It sounds like you are shooting a regular field pistol course and almost anything you can hit the animals with will knock them down reliably. I started shooting NRA silhoutte in 1973 or 74 don't remember , caused by getting old, and a fellow who shot an open sighted K-38 took the 100 yard rams over 100% on his hits with a 148 gr double ended wadcutter. You could almost watch the things fly down there but when they got to 100 yards they went thump and the rams fell over. So work up loads that are accurate and you will be fine. I always worked up loads that ran about 1200 so the trajectory would be much like my 22 LR barrel . Point of aim at 25, a little high on the pigs, point of aim at 75 yard turkeys and horn high on the rams at 100 yards--never readjusted the sights between animals. Shot in the mid 30's when I was on about 30 when I was so-so. I Used a 4X pistol scope at arms length no Taco hold ! I shot one round with a friends 32/20 with a Leupold 20X scope and shot a 38 just to prove I could shoot the non standard game. Never shot that way again don't feel that is how I shoot a pistol in the field so I won't shoot one that way in competetion. Good luck it is a fun game !
