I don't see why it wouldn't work scaled up. At some of the Games Days and Golden Demon events they ran 28mm scale EPIC (well technically Space Marine / Adeptus back then) games which really lodged in my brain. I just absolutely loved the five marines glued to a chunk of card (just like the EPIC bases) and the use of upside down crates as large buildings. Obviously they were using Armorcast titans. Absolutely brilliant stuff. There are a few photos of those games in White Dwarf, although off the top of my head I couldn't say which issue. Incidentally at the Titan walks I've seen at
Beachhead they were using upside down plastic pond liners as mountains - so the trend lives on!
I guess scaled wise you might have to reduce weapon ranges a little to make it practical space wise, although maybe not, I'd have to dig out my rules to see what they were like. I suppose you might need the titans mounted on suitable bases - I seem to recall orientation was quite important with markers on the bases for turning and so forth. Then I guess one issue is there are only a handful of Warlord titans from Armorcast in the world

. Still I guess you could make do with the smaller Reavers and so forth.
Obviously these days some people do play modern 40K with the Forge World titans - Apocalypse games I think they call them? I've never actually tried the classic Armorcast rules for Titans in a 40k game - did you ever try them?
How many titans do you have? I've a bit of an Armorcast habit myself and have two Reavers, two Warhounds and one Phantom. I suspect I'll try to avoid accidentally getting any more!
