In defense of the original poster, he did correctly adjust for what the equivalent maximum-for-class ERP would be at the heights for WTM, Capitol and the other sites. The FCC's FMPower calculator is readily available, and it does tell us that a full class C at 729m AAT would round to 63 kW, while KIRO-FM, for instance, is 52 kW.
It's also quite true, as Kelly well knows, that good consultants can make use of a variety of tricks of the trade to adjust the way HAAT is calculated in rough-terrain areas. You can use several different methodologies and tweak the number of radials that are used. For many years, the FCC had a policy called the "Denver waiver" that allowed some radials to be ignored; it got its name from the stations on the brow of the Front Range overlooking Denver, where the city and nearly all the market population are several thousand feet down below to the east, while the Rockies keep climbing for several thousand feet more to the west. "Averaging" the terrain in that case would present a misleading picture of how the transmitter site relates to where the listeners are.
The reality these days is twofold: first, that the FM spectrum has been jammed beyond full, and second, that there are now 70+ years of allocations and policy history that all play into the power levels that stations can use in the real world. The history of the short-spacing rules in 73.213 and 73.215 alone could (and often does) keep a good consultant busy for days. Those sections almost always have more real-world impact on what stations can do in crowded coastal areas than the "basic" spacing rules in 73.207 do.
And that's before even beginning to take Canada into account, and all the ways the treaties have changed over the years. Start reading about the allocations history of KING-FM with respect to 98.1 in Princeton BC and 98.3 in Chilliwack and your head begins to spin (unless you're the consultant or lawyer who gets the billable hours to figure it out, in which case your car payment gets made for the next few months...)
KING-FM is one of those stations using a directional antenna at WTM2. In its case, it's not for any sort of ERP-boosting trick - with 68 kW/707m it's already at class C maximum up there. It has no short-spacings toward any US station, though it's been jammed in nice and tight at its edges by 98.3 in Rainier and the 98.1 down in Seaside OR. It uses a directional antenna only because it doesn't need to send full power out of the market to the east. Right now, it could go non-directional if it wanted to take on the expense; at some point in the future, it could potentially get boxed in if another station were to assert 73.215 short-spacing against its licensed DA facility. That's a calculated risk.
Here's another one up there: KISW did need to use the directional antenna to manage two short-spacings that would prohibit it from going omnidirectional as a full C on 99.9 at WTM.
Turns out there is some DA protection to Canada up there, just not directly north or northwest: the signal that has to be protected by that little pull-in around 20 degrees on the DA pattern keeps KISW's signal from interfering with 99.9 at Oliver BC, and the deeper pull-in around 100-110 degrees protects 99.7 in Yakima.
