not quite true Andyy
I think you will find that Agusta designed the A101, A102, A109, A129 etc MGB prior to the EH101 so to say they had no experience is quite incorrect.
ralso remember that the EH101 MGB is one of the very few that HAS demonstrated a true 30min dry run capability so I guess they do know a little about MGB design.
When the aircraft was designed and developed the RTM322 was never in the picture. The Integrated Development programme that launched EH101 always intended to have 3 off Engines specified as GE T700s. ONLY when the RN changed the specification of the 101 to include dipping sonar with associated increase in AUM thereby making it a 'Merlin' rather than an EH101 did the change in engine come about. As much as anything to ensure that the UK helicopter engine industry survived and to provide a UK source of an expensive part of the aircraft (legitimate concerns for a Govt)
The 3 engine requirement was driven by CIVIL concerns regarding Class A t/o performance capability that was felt to be very important in the light of the BHAB recommendations following several North Sea crashes. Remember the target market was civil and military from the start and it was a judgement call that the two companies made at the time to 'compromise' the aircraft so that both types of market could be addressed. In hindsight this seems to have been a sensible decison as the crashworthiness and survivability driven by Civil rules has benefits for all users (sadly missing from CH457 and Puma) whilst still having a very impressive OEI flyaway capability (quite useful when hovering over the oggin)
DM