After a year since I'm played, here some accomplishment I've reach and get so far.
My high tier ships so far
1. For DD's
IJN - Yugumo (1st treeline), Akizuki (2nd treeline - my favorite); doesn't bother Shima since Shima is overate sh*t, my Aki can rekt them easily
USN - Benson, Fletcher, Gearing (all of them are fun to play)
2. For BB's
KMF - Tirpitz, Bismark, FDG (all of them freaking awesome including Sharnhorst (if I want to sealclubber), manage farm damage & achievement in battle from them) need 70k exp to unlock GK.
USN - Missouri (since I got her, I dont bother to look or farm other ships at USN BB's line (besides, Missouri is Ultimate Sniper Rifle

)
IJN - Amagi (but didn't bough her since IJN BB's line not fit with tea cup)
3. For Cruiser.
IJN - Mogami & Atago (rarely play them, doesn't fit my playstyle)
KMF - Chapayev & Kutuzov (rarely play them, doesn't fit my playstyle)
As for Captain Line on every nation - manage to got 9 captain with 19 skill points (3 at USN including Steven Seagal that I put on her Missouri, 3 at KMF line, 2 at IJN line, 1 at VMF).
Since every battle I manage to get 1.2k to 3k exp on Co-Op battle & 3k - 10k exp on Random, so u can do the Math which the reason why I can grind so fast.
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So far what I've spend premium account (for faster grinding & more credit income on every match) & doubloons.
Just use doubloons for captain reset skill & replace ship armament module. Never spend doubloons for exchange credits, captain experience or free EXP since both of them easy to grind & its not worth (with exception for Missouri case, & that's all

)
Doesn't spend single doubloons to buy port slot or captain reserve slot since RNG helps me a lot from container box (I mean I really got too many slot already - 14 empty slot for ships and 16 slots for captain reserve)
Got too much signal flag that I don't even need them (the economy & special flags, I don't even use it at all & I got too many India X-ray WTF )
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But for some unknown reason I felt satisfy & regret at the same time for grinding so fast. Already get my hand on every match from low to tier 10 match. For me every match are just the same, it's how u quickly adapt and analyze the situation; I play for objective on every match and help my team to win (even if I need to be a bait for my team - but as long my team know their role and support the others, it was a necessary sacrifice; AND BECAUSE I'M MANLY & NOT A CHEEKY.
Right now, I've done all the mission & objective on the game. I'm will go back to Co-Op again while grind as usual while practice using CV again.
Feel eager want to play CV line again this time, since I already rekt Kaga with my Saipan (with 3-0-1 setup) today & got myself another "Clear Sky" achievement today.
Inb4ImCVmasterRace.