Capt Flint he is a dread fleet --  the others are pirate units 

But each one of them Pirates/Even Capt Flint have some kinda graphic change

only one doesn't is the Marine, he is the only one that didn't change in looks on here and in game

So this is very confusing, 

So my guess is all of them, but the Marine

I will not count dread

Rest of them marine looks fake so 3 are remaining.

"Arrrr"

I say 4. 

Arrr

All but the marine be different so me answer be 4.

The answer to this could be a few different things, or perhaps an accumulation of different answers. Searching for the "odd units" is vague, because I can spot a few differences right from that start... *furthermore, it should be mentioned that when using the word odd in reference to one or more of something in a group, it should mean the minority.*

1) The Sapper and the Marine are the only ones not holding a "Bladed Edge" weapon, making the answer 2. 

2) The Marine and Captain Flint are the only two with guns as their weapons, making the answer 2.

3) The Zhangzou Elite's and the Dragon Lady are the only two units that do not have weapons that need Black Powder to use, which would make the answer 2.

4) The Sapper, Zhangzhou Elite, Dragon Lady, and the Marine are all in the "Pirate" unit category. Captain Flint is a Dread Fleet, making him the only odd unit, making the answer 1.

5) The Zhangzhou Elite's weapon has been changed, perhaps making him the only odd unit, making the answer 1.

6) The Sapper is holding the head of someone long gone, perhaps thinking she can blow things up with it, thus suggesting she's lost her own head, thus perhaps making her the "odd" one of the bunch. Or the fact that she is the only one in the bunch not holding something that is typically considered a weapon. Either way, makes the answer 1.

7) Depending on the mission in which these units were on when they were captured, there are an additional 3 possibilities: 

A) If the units were on mission to reinforce, the Marine and Captain Flint would be the odd ones because they are not defending units, making the answer 2.

B) If the units were on a mission to attack, the Sapper, Zhangzhou Elite, and the Dragon Lady would be the odd ones because they are not offensive units, making the answer 3.

C) If they were sent on a blockade, I say none are odd at all, making a possible answer of 0 to a tricky question. 

8) If by odd units you meant which ones appear different from their original pictures, the answer would be 3, as the Sapper, Elite, and Dragon Lady are all drawn differently here.

The answer could be 0, 1, 2, or 3, the way I see it... seeing how it depends on what specifically you are meaning by "the odd units". ;)

Arrr! I think I found more answers than anyone cared to look for! :P

arrr, my answer shall be three of them ! 

the marine and the dragon lady are authentically equipped, the rest differs 

(but it is good to know that Captain Flint found his long lost leg again ^^ )

Yo-ho-ho!

There are 4 odd Units in the Picture. Take a look!

Her posture was changed. Maybe she noticed an enemy and it made her extremely alert. 

5 random Captains who correctly wrote the number of fake Pirates receive 1000 Rubies!

Captains, PM me the coordinates of yer Havens. Arrrrr!

WINNERS

BOOTYMASTER

ICY

FEISTYFIONA

DAC2491

SEANOD77