I have Koni all around with Eibachs and 225 45 17 tyres it's a TS and never had an issue.
When I bought the car it had Koni with original springs - the Eibachs transformed the handling.
My plastic shock shroud is in the same position as yours (9.5cm from the centre of the shock bolt to the shroud ) although my dog leg is almost horizontal to the road like Clive's where as yours looks like it goes up at the wheel end but maybe it is just the picture.
I took time today to photograph the rear suspension on couple of my V6 GTVs fitted with Eibachs, one on Konis the other on std spec KYBs.
As you say the plastic shroud's low position is correct, it's just a lot longer to start with, & your measurement is spot on. Looking at the OP's picture it would measure about that as well, distance between bolt, base of shock body & bottom of shroud being approx equal.
Both my cars are parked in very awkward positions & not easy to lie under to photo. The one on Konis runs 215/45s instead of 225s, these were fitted before I got it(maybe to avoid clearance issues?) but it only had std shocks(completely shot, fronts were on the ground!), no bumpstops(still hasn't!?) but now doesn't rub at all. I've given this car a damn good thrashing on some very bumpy rural roads, so much so the cranks broken(another story
) & not had any suspension issues, ended up with the fronts set back to softest after getting fed up with the discomfort around our bad roads.
The one on KYBs has the shorter TS bumpstops but is running 8J 18s on 225/40 tyres, spaced out approx 10mm wider than a std 17" Teledial. I've driven this car hard to test the wheel/suspension combinations(having tried FK Coilovers, Apex -30, PI -30 & finally Eibachs. Also I've had it on 19" OZ Superleggeras(on FK coilovers
), 17" Teledials & now 18" Team dynamics, the last 2 with new OE spec shocks. No rubbing now or when on Teles or with the -30s with either 17s or 18s(didn't try the 19s as I fitted them to a GTV on KYB rear shocks, std springs & sold it).