Ships is a part of the game that has never had a lot of development or need until recently.
Because of this there are loads of people who never cared about fleet. From any era there will be shards that are super dead, and some that are super competitive. It's all about when you happened to hit 60 in relation to others in that time period and nothing else.
As far as GR fleets go the a-number one most important thing your fleet can have is a high relic maxed out JKA/ETA2.
You don't even need Hound's Tooth. I take first every day I try to without hound's tooth in my fleet at all and never drop out of the top 20. Now I am on a less competitive shard than some, but what works works.
Definitely agree about buying refreshes to climb up higher. The higher in ranks you go the shorter ahead you can be seen. At rank 7 I can be hit by exactly 4 people. At rank 200 I can be hit by something like 30 people.
Spending on refreshes to climb as high as you can is pretty likely to actually save you crystals in the long run simply because you will decrease how much you get hit by decreasing the amount of people you are exposed to. They can't hit you if they can't see you.