Meng are a newish company. Definitely one of the better new kids on the block. They have produced some imaginative and generally very good armour kits ranging from modern technicals (i.e. armed pickups) and the AMX 30 family to the WW2 Minenraeumpanzer and A39 Tortoise 32 pdr SP.
Their kits have gone down pretty well in terms of subject and quality, so this should be OK.
They have a slightly confusing way of naming their kit series after vaguely appropriate Mesozoic reptiles - e.g. the flying reptile Dimorphodon for the aircraft series. Perhaps it's a Chinese dragon thing. The FT is (rather too flatteringly) in the Tyrannosaurus series as one can see from the logo on the box top.
My impression is that Meng seek out a niche of their own in terms of neglected (in terms of modern quality kits) but interesting and/or important subjects rather than the usual series of Tiger (early early), Panther, Tiger (early morning of 28 April 1944 production), etc. etc. So I am not at all surprised to find Meng sniffing around - more than sniffing around - the Great War.
As for the third weapon, maybe it's the Riebel (if memory serves?) which was fitted postwar? They do say they'll include a WW2 colour scheme.
And the specific mention of the cast turret version makes me wonder if a bolted plate turret version is planned.
I also note the inclusion of independent track links - a big plus point. I have always been annoyed that RPM/Maquette charged extra for a proper link track set for their FTs, as the main tank kit did not even have useable vinyl tracks (the ones I have disintegrate unless treated very carefully).
I've seen the Meng A39 Tortoise at AMMS Brisbane. The guy who built it reported it was a really good kit without any issues of fit or production (flash/sink holes).
I should say I know virtually nothing about plastic kits - some images here