The Vittoria Mazza on Hope rims is a known knuckle-buster of a combination,
@Just gan. Hope's rim tolerances tend to run tight, and the Mazza bead is already on the stiff side. The fact it seated fine on your Roval rim means nothing, those two rims have quite different bead seat profiles.
A few things worth trying before you bin the tyre off entirely. First, leave one bead seated and only work the other side, pushing the seated bead into the centre channel of the rim as you go round (the centre channel has a smaller diameter, which gives you the slack you need). Second, ditch the Fairy Liquid and use proper tyre mounting fluid or even just warm soapy water with a sponge, worked well into the bead. Fairy can actually be too slippery and let the bead ping back off. Third, if you've got a ratchet strap, cinch it around the tyre circumference to compress it and force the beads inward while you lever.
As for tyres that go on without a fight, Maxxis are generally the easiest to mount of the gravity brands. The DHF and Assegai practically fall onto rims. Schwalbe Magic Mary is usually cooperative too. Continental Kryptotal can be a bit tight initially but loosens up. Vittoria and Pirelli are consistently the worst offenders for tight beads, especially on Hope and DT Swiss rims.
@Pezzar noted that even
fitting rim inserts with tight tyres is a thumb-destroying exercise, so you're not alone in the struggle.