This is just a random bit of speculation on my part. Recent waves have seen certain power builds emerge and one of the common themes is that they often involve spamming a particularly powerful ship or ability. U-Boats, tri-Defenders, TLT-spam, Attanni, regen. You name it, lists have been built around it. The meta is in an interesting place right now in several archetypes are jockeying for dominance. Lists that do well at tournaments are often the ones that happen to best counter the meta on a given day.
This smacks slightly of blind luck and I have noticed that consistent winners like Paul Heaver often play lists with different ship types in them. For example, his recent winning list at the Naboo Open was Miranda Doni, Biggs and a Stresshog. I don't count 2 TLTs as spamming in this case since one was locked in the forward position and was mainly to get double Stress.
Lists that spam a particular type of ship or upgrade are always going to be vulnerable to rock-paper-scissors syndrome where they win big against some lists (almost without trying) and lose big against others (almost without a chance). So perhaps the best reliable strategy is to build a flexible list that incorporates elements to deal with as many common meta-threats as possible. Paul Heaver's list is a solid example of this. Something to deal out stress is solid against Attanni and PTL Aces and has become even more valuable since the /x7 nerf in the latest FAQ. Miranda Doni is a rock solid pilot with built-in Regen and the ability to bomb opponents to bits with Sabine on board. Biggs makes sure that these agility 1 ships last long enough to make a dent in the enemy fleet.
I think that as the meta becomes larger and less predictable, varied lists back up by lots of practice will win an increasing number of events. Any spamming list is going to be too vulnerable to a hard-counter to win top tier events reliably.