The Spear you chose seem to be the One Handed version, you can choose the 2 hand (Great Spear) which has better stats for 2DP.
For a Monster hunter, hit and wound should be 3+ personally. The weapon change should help achieve that since it frees up the points.
Thematically, based on the Bonesplitta aesthetic, I would reduce his save to 5+ but give him Ethereal or Ward. Would also give it Frenzy or Zealot.
Named Characters usually only cost a few more points so to make him the whole 40, I would give him a Mount or Gargantuan. Can change his Archetype as well, Kruleboys did that with the vulture guy with a named wizard, but an unnamed warrior.
What is a Gnoggoth? That would help with the creative process.
Just my personal thoughts.