I'm talking about players who actually have talent, not your thompsons and Grant's of the world, you dont need a historical 4th line frost could play on a 4the line as long as he has other players with him, you've said several times he can't play a 4the line role, and that's because you want typical grinders and you're overly obsessed with size
I'm not obsessed with size, but as Martel showed, there is a minimum size below which the probability of NHL success approaches zero (in a league with 400+ forwards, there's always an extreme outlier or two). And young undersized players often struggle for a year or two before they get strong enough and experienced enough to handle the NHL.
Fourth lines are generally energy lines for a reason, they don't get regular shifts so they're not going to have the chemistry of a line that plays 14-16 minutes a line, and they don't have three skilled players, so they're unlikely to generate much offense (A player who is talented enough to play a regular role in the top 9 will soon be in the top 9). So HCs want players who hit the ice flying, willing to forecheck and hit and cause turnovers and make things happen, not patiently set up scoring chances for non-existent scorers.
That doesn't not describe Frost or Brink. Farabee could play a 4th line role once he filled out, as could Lindblom, but why would you waste their talents there?
Third lines are often compromises, look at Goodrow - Gourde - Coleman, Gourde is a skilled center who has accepted more of a forechecking role and thrived, the other two are career bottom six types:
Gourde, pp/60 ES, 2.65, 2.08, 1.49, hits/60, 2.38, 4.59, 5.00
Coleman, pp/60 ES, 1.38. 1.59, 1.69, hits/60, 12.26, 11.80, 12.13
Goodrow, pp/60 ES. 1.69, 1.23, 1.54, hits/60, 8.81, 9.54, 10.74
for comparison purposes:
Raffl, pp/60 ES, 1.39, 1.46, 1.70, hits/60, 5.62, 7.91, 6.61
NAK, pp/60, ES 1.95, hits/60, 13.19
Laughton, pp/60, 1.41, 1.76, 2.62, hits/60, 9.28, 8.47, 10.28
Pitlick, pp/60, 1.64, 1.18, 1.76, hits/60, 7.15, 9.67, 11.15
Frost, pp/60 ES 1.61, hits/60, 1.08
Bunnaman, pp/60 ES 0.62, hits/60, 9.01
Grant, pp/60 ES 1.88, 1.40, 1.79, hits/60, 5.83, 9.73, 5.20
Thompson, pp/60 ES, 1.30, 1.28, 1.14, hits/60, 9.94, 6.10, 9.50