Or they can end 2 season with Luffy defeat by Crocodile, so third season will be fight against Crocodile and Eneru. But I feel this will be also bad decision.
No. Unless you want LA to be dragged, kinda like actual OP Manga post TS. And no, it is not because Oda need more rest which is okay. The story post TS was kinda dragged, but that's different topic
As for LA, tbh it will depends on how many season they want to make (if they already has the plan).
If it is 6 season, then Marineford might happen at season 3 or 4.
The implications is, season 2 might have at least 2 big arcs altogether.
Oh. And I always think that Post TS (at least untill now) is easier to be compressed for LA than pre-TS.
For instance, you could cut Sumo scene with Urashima or some panel when BM randomly scream "Wedding cake" and the story will be more or less the same.