Attack of the killer shrimp

Sorry for the false alarm, no one was attacked. But I do have a question concerning these shrimp: Some 2 years ago I bought 5 green BabaultI Shrimp from my LFS, and one that was of brownish color. I never had any other shrimp species in my aquarium, nor did I buy any after that.
Some 6 months ago I started noticing that some of them grew really large (more than 3 cm, as you can see on the pic). Also, I noticed that some red specimens also stared to appear, and some of them had really intense red color. I didn't notice that any of them ever grew above 2.5 cm. There are a lot of questions going on in my head:
1. Do BabaultI Shrimp grow to this size (3-4 cm)?
2. Did a different (red) species sneak ih amongst the initial 6 I bought? Are the red ones just younger and didn't reach their full size?
3. Are they actually the same species?
4. Are they going to eat my healty plants once they get too big (I did notice dying off of sagittaria subulata, which can be seen on the last photo).

Here are some photos, and you can actually see two specimens on one of them for comparison (a red one and a large one)

Thanks

 

That red with the big green is a babaultI you can see the distinct strips, I think what's happening is you have reds being thrown out during breeding
The first red looks like a cherry so something could have hitchhiked in,
they do grow to 4cm but I'm not up to speed with these guys but the colours and throw back can't be that different from other species
They don't eat plants

 

Been doing some digging and came up with this,
Caridina cf. BabaultI shrimp – Detailed Guide: Care, Diet and Breeding - Shrimp and Snail Breeder

 

The title killed me.

 

That red with the big green is a babaultI you can see the distinct strips, I think what's happening is you have reds being thrown out during breeding
The first red looks like a cherry so something could have hitchhiked in,
they do grow to 4cm but I'm not up to speed with these guys but the colours and throw back can't be that different from other species
They don't eat plants

Thanks for the support I've actually separated the red population in a different aquarium ever since the red ones started spawning (the completely red one is from that aquarium). They werent this intensive at the beginning, but I did some selection by leaving only the ones with most intense color there .

 

That's a good way to keep control they will always throw out a red now and then it the same with black bee mine throw out the odd red,
Anyway good luck