My two cents on the topic:
In my opinion, with respect to mana/endurance, there's three basic categories of classes:
1) Pure caster. That's Wiz/Mag/Nec/Enc/Clr/Shm/Dru. They don't need endurance stuff because they have their spells.
2) Pure melee. Fighter, Monk and Rogue are really the only ones in this category. They don't have, need, or use mana. They need a lot of Endurance using abilities because it's really all they have to draw on that is 'nifty'.
3) Hybrid. That's SK, Pally, Bard, Ranger, and Beastie. All four have casting... but it's not as spiffy as the pure casters. For that reason, I think all five of them should have some endurance stuff as well.
Now, let's look at their stance options
/s 4 reduces their aggro generation, which is one of their main problems.
/s 5 trades off accuracy for haste... not so sure this one is really worth it. You can get haste several different ways, and there is possibly a stacking issue here. Besides, if you miss an equal or greater percent of the time than the haste generates attacks, it's a net sum loss.
/s 6 seems cool until you realize that it really isn't all that effective because it runs out quickly and a mob isn't constantly trying to cast all the time. Maybe this should be an activated ability that automatically interrupts the spell being cast by your target for a flat endurance cost and maybe a reuse timer?
/s7 means your pet goes down fast in any raid situation, which is counter-productive, because then you have to re-summon, then pester the mage for silks, then collar, then see what kind of pet weapons you can put back on it... this is definitely counter-productive on any raid, but moreso the higher tier you get. Pets are high-maintainance already, this makes that problem worse.
So he really has no options here. /s4 all the time, every time.
Now, let's look at stance options for a Ranger, who is the other DPS-focused hybrid class:
/s 4 trades off DPS for survivability. Handy if you suddenly have drawn aggro and need to tank it until the real tank can get it back.
/s 5 is increased melee DPS for a burst. However, at higher levels, it's meh because you're doing most of your DPS with your bow, the DPS boost is relatively minor, and it drains your stamina fairly rapidly. Not useful for the raiding ranger.
/6 is a 'Tank down! Someone get this off of me!' button. Extremely handy on a raid to give the offtank/secondary tank time to apply a snap-aggro tool and prevent a raid-wipe.
/7 is burst DPS. This is what you do when the Enchanter shouts 'STRIKING CURSE ON!', or 'Healer at 10% mana, BURN IT DOWN NOW!'.
/8 is the stance you are in 90% of the time on a raid, because you're standing back with the clothies racking up amazing DPS with your bow. Considering even with the drop in defenses, you're still more likely to survive something jumping you than a clothie is... not a major concern. You'll have time to switch to /s 6 if the raid target jumps on you.
So we see here that he's got three main stances that are viable in a raid... one that increases DPS, one that is a 'prevent a raid-wipe' button, and one that is a burst-DPS button.
The beastlords have none of these options. And really, if you've got a solid raid-tank, the beastlord isn't going to jack aggro anyways, since his DPS is nowhere near what, say, a Ranger or a Rogue's is.
In my opinion, a Beastlord needs something to do with his endurance. Something that will be viable in a raid. A burst-DPS button would be a good thing, something that drains stamina but increases his DPS. After all, they're supposed to be a DPS class, right? Also, they are the only melee class without a 'tank down, get this off of me!' button. Granted, they generally don't need one because every other melee class is ahead of them on hate, but that's something that needs to be fixed as well.
You want to give Beastlords a useful raid tool? Give 'em a stance that gives them a reduced chance of being hit by a riposte. Beasties can't take the hits that most of the other melee classes can, and you can't always position yourself behind the target because of the encounter script.