Combat Blades are onlygooduseful in Melee.
Pistols are only good <12".
Terror Troops basically only works when they're engaged.
Picking up Outflank or Death From Above, is mandatory for Reivers to not be actual garbage. Which makes them 20 Points each.
So you pick up those Knives for any Melee Chapter, sure. That could arguably work. Because it's CP-free Reinforcements, and Terror Troops does have value, and if you're going to be Charging an enemy unit; You can always turn off their Objective Secured...But remember that Reivers aren't ObSec either. So it's benefit is very, very situational. But certainly not useless.
If you're talking about Bolt Carbines...S4, AP-, in the Elites slot, of all places? Choose literally anything else. That sounds like one of the worst units in the Codex.
Try and convince you're opponent that they're Infiltrators if you really, really like the models (some do, I think they're hideous).
Phobos-heavy armies tend to skew Melee in the end. Only because Incursors and Vicky Warsuits are that good.Anyways, here's where my rebuild is standing right now, Prefer keeping them Ultramarines (especially since I have Guilliman, just not sure if I can justify his points cost yet. Unit suggestions anyone?
But, since you're talking about Ultramarines...I've been inferring that Ultramarines can play Melee - not that they should. But certainly they can. All the good Melee units are typically Firstborn, so that might be a problem. Otherwise, Ultramarines are Space Marines, and Space Marines are shooty. Just pick up all the better units.