[Fluff] Mark IIA Hover Rhino and conversion

So originally I mage the mark IA (fluff below) but then when I made my recon marines I decided they needed a transport akin to the land speeder storm.  What better to transport my Mark IV scouts in power armour than an armoured hover transport (land speeder storm counts as).  Since I already had one, this was perfect.  Though it needed some weapon upgrades.  I hope the fluff makes it somewhat plausible (I only really need to convince myself haha) and makes an interesting model.  After a bit of cutting I have this.  Any thoughts?

The Mark IIA Hover Rhino was seen as an improvement over the original Mark IA design and is still in production today, albeit limited, within some Chapter forges.  By reducing the thickness of the armour plating, the weight was drastically lowered while the engine was enlarged at a cost of crew transport capacity.  This resulted in increased engine performance and lift; an overall improvement from the Mark I.  Capable of attaining altitudes of hundreds of meters while transporting upwards of five battle brothers, the Mark II's battlefield role is typically utilized in flanking manoeuvers into hostile terrain in lieu of the less armoured Land Speeder Storm. 

Usage by the Emerald Fists has increased since the Schism; most notably among its scout squads.  The increased protection offered by the enclosed ceramite hull paired with its servo-assisted weaponry is an invaluable tool to safeguard the future of the Chapter.

And the original with fluff:

The Mark IA Hover Rhino was created near the end of the Great Crusade by applying anti-grav technology discovered by Arkhan Land; a technology more common to the Land Speeder which bears his name.  The Hover Rhino did not enter widespread service due to problems with the reliability of its engines.  For a vehicle whose prominence was owed partly to its machine spirit's resilience, the However Rhino's inability to match its predecessor's stubbornness was its ultimate downfall.  Although prone to breakdown, its unique design allowed it to reach greater speeds and traverse terrain not approachable by typical APCs.  This reason, paired with limited production numbers, saw the original Hover Rhino issued primarily to command squads among the legions. 
The relic shown here was passed from the Imperial Fists to the Emerald Fists at their founding and was looted by traitor forces during the Schism of the Fists.  The temperamental machine spirit renowned among these vehicles has been appeased by the warband's warp smiths though undoubtedly unconventional means.