Quote Originally Posted by Cheesegear View Post
AdMech: NO ALTERING THE STCs! YOU'RE ALL GOING TO HERETEK HELL!
Techmarine: Err...Are you punishing us for winning? Because mounting a Demolisher Cannon on a Land Raider is totally sweet and we're doing it from now on.
AdMech: Uh...Err...Tell us how you did it. Make us a new STC and we'll let you live.
In fairness, this isn't the only way to interpret the same scenario.

Techmarines are, after all, members of the Ad.Mech. and as such can be expected to be privy to their sacred rituals and the necessary absolutions needed to make such drastic alterations.

It might not be the case that a Techmarine, pushed by dire circumstances, has to jury rig something nigh-blasphemous that he later manages to defend under the same tactica that GolemsVoice just mentioned.
It could well be that there are rituals, prayers and sanctified circumstances already in place that exist to allow the splicing of two vehicles and/or weapons like that. There's no reason to think that the Ad.Mech DON'T have competing factions - like the Amalathians versus the Istvaanians of the Inquisition - that might favour or revile different interpretations of the Omnissiah's will in similar ways.

Which, I think, is one of the better parts of things like the Ad.Mech. being so vaguely defined in the canon - this could be a very interesting way of getting promoted to Magos in the first place. Someone receives 'divine inspiration' for a unique technological solution to an existing problem (in this case, getting Demolisher Cannons close enough to be used), spends a decade researching the correct prayers and rites and making sure that they are compatible with the theology, and then undertakes an immensely solemn and strenuous ritual under the watchful eyes of his superiors to create the first prototype.

Assuming it works, and his 'psalms' are judged to be appropriate and devote enough? Congratulations! The Omnissiah walks with you, here's a pay rise and a new name tag. Get to work, Magos.