Well, if you use an amount of HCG yielding high normal testosterone and that is the only source of increased testosterone, then all else being equal the amount of LH suppression is the amount typically occurring while having high normal testosterone. In other words, perhaps not maximal LH production, but hardly severely suppressed either.
Now if you use the same HCG dosing but add some injected testosterone to it, this is not an equal comparison as now you have more testosterone and, all else being equal, more estrogen, so why expect only equally minimal suppression?
Even if NOT using the HCG, 200 mg/week testosterone by injection is reported to yield about 2/3 suppression.