The Britax Max Way Plus is one of the safest seats in the world as it's passed the Swedish Plus Test which is the toughest test to pass. It also has a support leg and tethers which makes it really secure, and it has extra side impact protection, which Britax do really well.
The Two Way Elite is older, braces on the front seat rather than using a support leg (probably just as good, although potentially easy to get wrong which would be bad) and the side impact protection is more basic/dated - probably equivalent to the Joie seats. It's not plus tested because it's too old and it can forward face.
The Joie seats don't have these features, only the seatbelt around the back to support the child in an impact. That doesn't mean it's bad, as rear facing in itself is inherently very good and supportive - even a lower quality rear facing seat performs better both for neck loading and other types of injury compared with the impact shield type seats.
The Joie seats rear face up to 18kg - do you know what age your other children reached 18kg / do you know what weight centile your DD is on now or what she weighs now? Both Britax seats rear face up to 25kg - so again you can predict this by looking at the age your other DC were or following DD's line ahead in her red book. I can look it up for you if this is confusing.
The Britax Max Way Plus is a purely rear facing seat, it doesn't forward face, but that's probably fine as by the time your DD outgrows it or you don't want to RF her any more, she can probably move into one of the other DCs' seats.
Citroen Picasso is a fairly roomy car, I think? So should be OK to have three across - however - does it have storage boxes under the floor? Those are a problem with support leg seats and Britax tend to say a flat no. So you'd have to check whether you can fit the Max Way Plus in the middle in that case. The Two Way Elite would be OK as it has no supporting leg.