I've had great success specializing entire units to one weapon type, concentrating the effort so they become very efficient against the target of choice.
I run a unit of six Caresses (counting the Troupe Master) in a Starweaver. This is dedicated to heavy vehicle, high T and Elite unit eradication. They're also armed with Neuro-disruptors for added killing power against 2+ targets, but the focus of this discussion is the close combat weapons. In that regard, Caresses coupled with sheer attack volume improve the chances of at least scoring one auto-glance if not more. Granted, you'll have occasions where they fall flat--this is a dice game, after all--but you'll also have those turns where you absolutely light up the target.
My other two units are dedicated to Kisses and Embraces, respectively. The bonus you get out of the Kisses is its combination with initiative. As the Troupe Master is Ix and the Players are Ix, odds are high you'll be able to have both attacking before the Challenger can return the favor in close combat. That means you get an extra number of Kiss attacks equal to the number of other models in the unit. Let's say you're going after a Captain level character. The rest of the Troupe is attacking the rank and file outside of the challenge. Resolve your non-AP2 wounds first, then the AP2 wounds. If you're fortunate, you'll have some extra AP2 wounds that spill over into the challenge as everyone else in the unit is dead. This can only be realized with larger units that are entirely composed of Kisses.
The other advantage you get with Kisses is the ability to handle most Dreads in close combat. Greater opportunities to glance means a greater opportunity to wreck. Close combat with most other vehicles are also going to get penned more often. While you do stand a chance at an explosion that kills some of your models, some vehicle blow-ups may well be worth it.
The Embrace is incredibly efficient, especially if you have the unit in a formation that allows for the Run and Charge. I have been able to devastate vehicles, Walkers, swarms and MEqs with equal effectiveness by virtue of tremendous volume. While you might think the odds of getting many men in base contact to reap the benefits is hard to accomplish, I can speak firsthand to the ease with which I've been able to get no fewer than 6 out of 9 models in base contact on the charge. With an average of 12 free Sx attacks at Ix, that's incredible output. Against Walkers, you can Run and Charge to get as many in rear and side base contact as you can in order to take advantage of the one loophole around having to face a Walker's front armor all the time in close combat. And hordes HATE this weapon. As most horde units are no faster than I5, you're not only going to get 12-18 S6 hits on them with their weak armor, you're also going to get your own units' subsequent normal attacks at Ix and Ix. With enough successful wounds, you can get to the point where their models can't even move within 3" of you.
Against vehicles, you don't have to worry about explosions like you do with the Kiss because your HoW attacks aren't AP2, so it's very easy to glance a vehicle to death before you even have to take your normal attacks. That's huge. This also means there's no penalty to doing a disordered charge against multiple vehicle units. If your opponent is obliging enough to place different vehicles in close proximity to one another so that you can accomplish dual charges on side armor, go for it!
One drawback to the Embrace is its ineffectiveness if you're charged or stuck in combat. Thankfully H&R will resolve that for you right quick. The other drawback is that your HoW attacks against a spread out horde could lead to your inability to pile in 3" to attack on your normal initiative. That's where Run and Charge to the densest parts of the horde can really pay off.
The power swords are, in my opinion, not worth it. The exception may be the Storied Sword. I'll be trying that out for the first time this weekend, so I can contribute more on that afterwards.
I really think having each weapon represented wholly by single Troupes is the best way to go. While specialization may lead to exposed weaknesses due to inflexibility, I think the mobility of the army with the crossover effects of all three weapons against vehicles makes up for them.
Edited for excessive stats. See forum rule 1 for further details - Iris.