That’s what Galaad seems to be suggesting should be done. Only those who complete the team achievement marks reap the benefit of said team achievement, which to me just feels sort of like individual achievement.
I can understand the “fairness” aspect of it, but we exist in a game where a team of utter scrubs could theoretically win a war against a team many times more powerful than them just by having one single gargantuan player backing them for 250 flames. So we already reward teams on the basis of their strongest members anyway.
My initial suggestion of those varying marks for both members and point level hit would allow the biggest members of a team to give those extra reward bonuses to their team. I can see why people want want to do that and might push that extra little bit more to give the bonus to their mates. I think locking the reward payout for a team achievement just for the ones who hit it defeats the team concept in a big way.