I'm not sure either of them is deserving of HOF status to be honest. Hoernschmeyer was chosen to 5 post season all star (all-league) teams in his career. 1946 and 1949 in the AAFC, and 1951-53 in the NFL. His two first team selections were both by the NY Daily News only, while he had 5 mentions on 2nd teams.
Trippi was chosen to 3 post season all star teams, with only 1948 as a first team mention. Trippi did have the 2 or 3 standout seasons while Hoernschmeyer seemed to be more steady across his career in production. Trippi also had the outstanding performance in the 1947 Title Game, and that is the type of thing that gets remembered. Hoernschmeyer made a contribution in two title games and did score a TD in one, but Trippi's 1947 was by far the flashiest performance. (Everyone here knows what games Max McGee and Jim O'Brien and Doug Williams and Timmy Smith are recalled for I am sure.)
Trippi probably was done no favors as far as a HOF argument goes by being switched to QB. Being switched to HB appears to have helped Hoernschmeyer.
If anyone here has ever read Bill James excellent book on the Baseball HOF and it's workings, The Politics of Glory (a later edition was titled Whatever Happened to the HOF?) He did a comparison of the value of Don Drysdale and Milt Pappas. They had identical career stats but Drysdale had the more outstanding individual seasons including a Cy Young Award campaign. By running simulated seasons with identical teams except the presence of either Drysdale or Pappas on the pitching staff through a computer thousands of times, they found the pitcher with the "Drysdale" pattern of career (Trippi sort of, in our discussion) produced far more pennants in the simulations than the "Pappas" simulations did.
Going by that, I suppose if the two men are competing for just one bust available, the right man got it. The 1 or 2 "Big seasons" are always going to make more of a memory impact on HOF selectors/voters than the steady compilation of good seasons. A lot of people think Indian Bob Johnson belongs in the baseball HOF, but he stamped out season after season of good solid performance like a machine, without ever having a "Superstar" type year. So, despite good solid numbers for his career, he remains outside the HOF. I think that's probably true of Hoernschmeyer for his era as well on the football front.