Designed by the notoriously fey P.H.A.Z.E. special projects agency rather than the Bureau of Mecha Design, the Lucerne is a peculiar machine that nonetheless fills an invaluable role in the CPSF.

The majority of mecha designs tend to fit into a broad category; some examples are 'troopers', slow mecha mounting heavy armour and firepower built to act as an 'anvil' or defensive unit, 'cruisers', fast and well armed mecha intended for flanking and anti-scout work and 'skirmishers', fast mecha with long-range weapons intended to harrass an enemy on their own and provide valuable fire support when acting in a larger force.

The Lucerne, rather like the Hydra it often accompanies, is made conspicuous by its distinct failure to fit in any wider category of mechae. The Lucerne is the Lucerne, and attempts at shoehorning it into ready-made slots tend to end in tears.

To begin with, the design is unusually swift for its weight class. Most heavyweights are slow and mount large weapon loads, as the engines required to meet a certain speed become prohibitively heavy very quickly in larger machines. The Lucerne certainly has a heavy punch; half of its chest is engine. The other half is cannon.

A Fitzroy 26cm quickfirer, to be exact. Weapons of the Fitzroy's class are uncommon in non-superheavy designs, not so much for their sheer mass as for the significant amounts of ammunition needed to keep them in the fight.
A Class Ten autocannon can be kept fed for any reasonable frontline engagement with three or four tonnes of ammunition. Feeding a Class Twenty autocannon for a similar period requires significantly more ammunition, even after factoring in the comparatively short effective range.
Nonetheless, the unmatched armour shattering capabilities of an assault cannon cannot be overstated; a single burst is enough to unbalance most mecha and blast off more than a tonne of armour.

On the subject of armour, its load is usually considered 'enough', though it is not quite as heavy as the Bureau would like. With luck, newer armour types currently being prototyped may, in the future, allow the design to mount enough protection to meet BuMekDes requirements.
As things stand, the battle-proven design is a gigantic walking middle finger aimed at the Bureau of Mecha Design, who discarded the early prototypes as 'too fragile'.
The engineering equivalent of a declaration of war, if you will.

Still, the Lucerne is a very uncommon design outside of the Coalition, and is only really widely produced inside the Coalition because it is, at the present time, the only machine with its raw firepower capable of keeping up with a strike section.