Ummm yes, it was an option. Solitaires can be given ANY option in the Harlequin Armory. And no the Solitaire isn't dangerous without it.
why? Heres two configurations of Solitaires:
Solitaire a: Harlequins Kiss, CC weap (or pistol). 101pts
Solitaire b: Powerblades, CCweap (or pistol). 106pts
Solitaire c: Powerblades + HK. 115pts.
lets say max attacks. we're charging from 6". 12 attacks, 3+ to hit. about 7 go through. Control will be against MEQs.
Now Solitaire A, is going to wound 83% of the time. Causing about 6 wounds. MEQ will save 66% of those, meaning 2 die.
Solitaire B, is going to wound, 33% of the time. Causing 2 to die (ignore saves). Same result as Solitaire A. 2 die.
For 90pts base, plus how much the wargear is. A solitaire vs. MEQ's is pointless as even with 12 attacks on the charge it won't cause any damage. Especially because I didn't spend any points on the D-field the chances that he'll survive one combat is close to nil. ESPECIALLY since Solitaires can't join units (other wise I wouldn't say anything, because the extra hits from a squad would nullify his weaknesses).
Solitaire C, 12 attacks, hits on a 3+, wounds 83% of the time. Is going to cause 7 hits, and 6 wounds which can't be saved. For 125+ points (still should buy the upgrades). This is closer to the damage potential I would expect from the Dancer of Slaanesh. Let alone this is from the closest charge range.
Any farther away and Solitaires A/B both suffer tremendously.
And please let me reiterate, not only was this an option. But, the entry on Powerblades specifically states that they can be used in conjunction with other weapons. This wasn't cheese, its how Gav Thorpe intended it.