Well there was that time he had the CCAF chase George Hasek headlong all the way back to New Syrtis but left the back door unguarded, letting the WoB bite a huge chunk out of the CapCon. Come to think of it, allying with the WoB in the first place was a mistake. Then there was that time with GOLDEN FORTRESS in 3081 where the new Republic of the Sphere punished the Capellans for their Chancellor's hubris. We got a re-run of that later in the Capellan Crusades.
It's not like the CCAF's successes were all that spectacular either. Guerrero only reclaimed a tiny portion of lost Capellan worlds, and only then with the help of Marik mercs. Comparing the maps of 4SSW losses vs Guerrero gains, the Capellan showing in '57 is quite a pitiful riposte. St Ives War? It took the CCAF four years to grind down a tiny rogue province, and that was with the help of two Periphery armies. Pushing back the WoB during the Jihad was only possible due to the Blakists being engaged on all fronts. The Victoria world ended with the Capellans losing two factory worlds, one of which was a commonality capital, and were left with a shattered military for the gain of a handful of non-descript border worlds (though the CCAF did absolutely crush the Anduriens).
Really the only time I see the Capellans doing anything seriously impressive is at the 'current' point in the Dark Age timeline, where they're clearly rampant. But then that's not even Sun Tzu in charge, and I'm not betting against Julian Davion right now either.
Prior to 3067 WoB was a legitimate faction and trading partner in the IS, in the eyes of at least two Houses and various other entities. IIRC some were please about that organisation splitting with ComStar, despite the religious trappings, because now there was a competitor in the HPG market.
Handbook: House Liao describes how Sun-Tzu pitted the two orders against one another, to the CC's benefit, when he was laying the groundwork for Guerrero and
Xin Sheng, so allying with WoB in itself wasn't a mistake. If he made any error, it was in not expecting WoB to hit another House capital or open a new front with his nation after he'd helped kill their beloved Star League.
I think Sun-Tzu's achievements are spectacular not because he made 4SW-style gains or had a flawless track record with his wars, but because he made any gains at all for the post-4SW CC and left the nation in a much stronger position despite his own follies. I don't see it as author fiat for the CC to have gained what it did in '57 and '63 when Sun Tzu did what any sane ruler would have: get his people's energies fired up in support of his goals, make alliances with states in a position to help him, and take advantage of his enemies' weaknesses at a time when he was numero duo on their threat list. Things certainly didn't go so rosily for him after '67, that's for sure.
That being said, Sun-Tzu taking Tikonov the way he did seemed a bit too clueless even for Victor. At the very least, dude, don't leave a die-hard Capellan unit on one of Sun-Tzu's primary objectives - send them to Pleiades to fight Taurians instead!
