i think the main concern here for people is the “combination” of challenges, when it comes to non-slayer objective modes, or in slayer, betrayals.
lets say for example we have these challenges;
win 3 capture the flag games
kill 10 spartans with a sniper
win 3 match made games
kill 10 spartans with a shotgun
this is a general example of what they did look like during the flight.
now lets say these can all be completed just by playing capture the flag, but for some reason, you or people your playing with want to complete these as fast as possible in the least relaxed way possible and the most optimized.
and they can’t get their hands on a sniper rifle, or they can’t carry the flag because they have a shotgun, now our issues are, this player would rather get kills than run the objective, and if betrayals are enabled, they will be betraying you for trying to run the flag, or for holding one of these weapons.
then after they betray you, you boot them, and your down a player, ideally this would be happening on both teams so your at least both down players, but one team, and obviously not your team cause you don’t have that kind of luck, is now completing their challenges by spawn killing you, in capture the flag.
and when they complete the kill x spartans with x weapons they’ll take your flag and win.
though that sounds almost better than spawn killing you in a regular progression system where more kills is more experience points.
maybe my point is that you can’t stop people grinding progression from spawn killing you, and maybe my point is that this could certainly leak into other game modes.
an easy fix would be tying combinable challenges to objective based gameplay, … betraying is still an issue, but you could tie kill spartans to slayer modes, and win modes to any mode.
so we would then say with our challenges that the fast way to complete these is to play slayer, then afterwards play capture the flag.
is that fun? eh, not really. but you where planning on playing big team battle anyway, and that has slayer and objective modes, so just have fun for a little bit and all these challenges will probably be complete before you know it.