Outside of wet conditions and true mountain terrain, trail shoes are often overrated. I'm pretty sure Rob Krar won Western States at least once in Lunaracers. I'm also pretty sure Walmsley was wearing Adidas Bostons during his infamous first attempt at Western State. And I believe Hal Koerner won the Angeles Crest 100 in Adidas marathon flats. Probably Western States, too. I'm no elite, but back in the day I put in some good results on technical terrain wearing Mizuno Ronins.
Even on mountain terrain, I know two skimo racers who both placed top 10 at Speedgoat in past years wearing road shoes (Hoka Claytons and New Balance 890s). And Sage Canaday won one year in Hoka Huakas, which hardly qualify as trail shoes.
The fact is, many super light trail racing shoes (e.g., S-Labs) aren't too different from road shoes.
I know you said "short" trail races, but again, unless we're talking about highly technical terrain, there's just no need for trail shoes most of the time.
Also, wearing road shoes is a flex, similar to elite XC MTB racers choosing road shoes :)