I would disagree. The short straight "spring" will have to deflect to a greater degree than the long curved "springs".
My thought exactly too.
I'm thinking a "hard coupling" incident might cause some failures too even if the coupler can withstand regular train forces, given how resin behaves from my experience. Maybe not even immediately, but say just a nice little crack to get things started.
"Randomly" breaking couplers will add prototypically accurate operating challenges though!