I wouldn't say the sound of a true vintage analog and its whimpy poorly sampled counterpart is very subjective. Put a Memorymoog in unison then play one note of a Moog like sound on your Tyros 4. Heck, go ahead and stack the Tyros 4 sound a few times to give it a fighting chance. Now play them side by side and see how poorly the Tyros fares. Do the same with the Jupiter 8 or OB-X versus your Tyros 4. That vintage synth pack isn't going to come close.

There's a reason people use vintage synths, its because nothing else sounds like them. Unless you're willing to do multisamples with a minimum of 5 seconds each, no looping, and sample each or every other key, you're not likely to come close to the original. This would require massive memory which would well exceed the total ROM that the Tyros 4 comprises.