Hobart's Funnies are a category on their own.

Only C has foldy wings. A & B certainly don't share the same airframe either. In terms of G capability it's more like A > C > B.

And as for badass british mil machines, it's got to be some flavour of nuclear sub

A folding wing uses up a lot of internal space which is already a premium on the B and requires a bulky heavy support structure which will eat into what the lift fan and engine can lift. The C has larger wings to create extra slow speed lift for shorter launch and lift offs those larger wings give it a space problem, the B provides its own stability via engine and roll posts so such a large wing is not required.

Both are compromised in design in order to suit the needs, a B with a larger folding wing would have a very low max take off load and higher loadings on vertical landings and a C with the smaller wing would be unstable on launch / landings.

(As opposed to)?

Neither was the Sherman! Given the choice I'd prefer to be in the slow and heavily armoured Churchill; an AVRE with the gigantic petard mortar for preference.

The $291m was a 2011/2012 LRP batch production cost as well, its expected to drop to half of that in 2016 when the bulk enters production and the orders for our carriers come through. The UK only has two at the moment and they are both still in the states for training.

Not heard of the B2 then?

The USAF originally wanted to buy iirc 130 of them but budget cuts meant they only got about 22 one of which has crashed.

The problem was the design and development costs pretty much the same no matter how many you build so when you load the D&D costs onto 22 airframes you get a $2 billion bomber!

Bill Sweetman wrote a good book on the B2 (ISBN 0-87938-599-5) which details how the costs went pear shaped.

Both wrong. The Titan and the Trojan are neither "versions of Challenger 2", nor are they "Chieftain based". Both Titan and Trojan are purpose designed and built specifically for the Armoured Engineer units of the Royal Engineers. They are in fact the first 'off the drawing board' designs for use in their role, as opposed to previous vehicles which were converted to the role from surplus gun tanks (both Centurion and Chieftain).
They have been designed to replace the last of the Chieftain AVRE and AVLB. The Challenger 2 connection comes from the extensive use of parts bin items from the Challenger. These include powerplant, drive train, and suspension/track parts, all attached to a purpose built hull. This results in better commonality of spare parts with RAC units, less strain on Log Sp chain, and transferable skills between REME units supporting RAC/RE units. It also means that, unlike during Op Granby in '91, RE units with a responsibility for providing mobility/counter-mobility operations can at last keep up with the battle groups to which they are attached. Back then we struggled to keep up with the battle groups, who were operating Challenger 1, whilst we were driving a mix of Mk5 and Mk6 Chieftain based vehicles, and where the infantry were zipping about in Warrior IFV, we Sappers were miles behind, struggling to keep our 1960's FV432 APCs running at all, let alone keeping up with the infantry.

Back toward the OP, whilst the GPMG may well be BADASS to the max, the Bren must rate pretty highly too. The 7.62mm LMG I took to war in 1991 was converted from a .303" Bren, dated 1944 . The same basic weapon in service for close on 50 years - not to be sniffed at.

Sappers do it with High Explosives!

In which case the photo in the OP referenced article is not a Trojan...or it it is, it's be retro-fitted with Chieftan running gear...