This is why I prefer AR starts with the pistol. Halo 5 IMHO is more exciting and dynamic with something other than BR starts for once. I like CE for this reason. All the weapons had a decent use in the sandbox. Halo 2 actually had watered down gunplay due to it revolving around BR all the time (exception was button combos). Halo 3 was super bland compared to halo 2 competitively because of the maps and issues with the BR in that game.
Halo 5 has given us a great competetive game (so far) without resorting to watering down the sandbox. IMO this means it's initial design is far better than what bungie did with Halo 2 onward. Bungie didn't want BR starts but it played horribly without it.
TLDR; the other Halo games played better without the default starts (and watered down sandbox), but Halo 5 is proving to break away from that trend. This is a good thing.
To criticise BR starts in H2 and H3 then hold up CE as a bastion of a rounded useful sandbox is laughable. The notion of every weapon being useful in CE when compared to the later sandbox's is a tired myth. Go watch Ogre 2 gameplay VOD's from 2003. Guy doesn't touch shit except snipe, rockets and occasionally shotgun, and you'd pick all those up in H2 and 3. On the rare occasion I see someone use the AR in CE for actually shooting instead of activating a glitch they get annihilated by the magnum.
I have to say AR starts are more tolerable in H5 because of the smart scope. Ar (or SMG) starts are instant quit worthy in H2 and 3. BR starts are still vastly superior in H5 however. I'll support Funknown's anti-radar campaign with more lustre than any of the previous games because the AR is
strong in H5, so strong that getting the 'jump' on somebody is almost a guaranteed kill within a certain distance. Because of this, crouch walking has become an even more effective tactic than it already was in prior games and the playerbase knows it. At least a third of the killcams I've seen in the AR starts beta showed the opponent crouch walking. It was ultimately harmful to map movement. BR starts have shown significantly less crouch walking in my experience.
Oh and for the first time ever, I'm picking up an SMG or AR as a secondary, even when spawning with a BR. So BR starts are not annulling the sandbox like some are claiming.
People talk about sandbox variety as if variety is inherently interesting. If you offered me a sandbox based on five different automatics or one precision weapon, I'd take the precision weapon. It's not really about the relative strength of the AR to the BR, it's about how compelling the gameplay is that those weapons produce.