In response to your question, Choice Band Tyranitar and OTR Bronzong just have excellent synergy together, and they usually aren't as expected as other sets that they would usually use.
OTR Bronzong is an excellent late game cleaner, Tyranitar has solid defensive synergy with Bronzong, and Pursuit Rotom. It can also 2HKO Skarmory, which is a major counter to Bronzong. Bronzong can explode on stuff like Swampert, and Tar can just clean up afterwards. Tyranitar also adds to the residual damage with his sand.
I have been using that combo since August last year, and posted a RMT using that combo in December, so I can really attest to its effectiveness. I would reccomend them together as partners to anyone who might want to build a team around them, or on a slow paced Bulky Offense team with stuff like Heatran/Dragonite. Tyranitar, Heatran, and Dragonite can outrun a large portion of the metagame in Trick Room conditions even with speed EVs so it is pretty cool I suppose.