Sorry, I still don't understand. Unless Tillig are doing something radically different to everyone else then, for most models, a newly tooled chassis will be required, unless they're going to produce some sort of caricature model. Of course they could use some existing components but some of these, eg motors, are probably bought in anyway so probably not a massive saving (pennies / cents)
I'm fully aware that Heljan don't make models in TT but it's not really relevant, is it?
I believe that Tillig still manufacture in Europe so probably not competitive with China (yet).
Of course they might do but then again they might not.
Going back to Heljan again, having tried to fix a few of their models, i do find it surprising how many non standardised components they seem to use (no, i wont be keen to take one apart in future). Perhaps Tillig are different?