Technical Question: Road vs Tri saddle position

I have a road bike & tri bike with identical saddles on both bikes. For the road bike, I keep the front tip of the saddle just behind the bottom bracket. For the tri bike, it is just in front of the bottom bracket. (Cranks are the same lenght). The difference between in position of both saddles is about 2 inches.

Question: How much of a difference in saddle positions is too much? For instance, can I extend the saddle on my tri bike so that it sits 3 or 4 inches farther in front than my road bike saddle? What do you do? I regularly ride both bikes and want to be able to work the same muscles on both bikes.

I’m only looking at the saddle (relative to the bottom bracket). Assume the stem/bars can be adjusted to fit your body properly on the bike given any saddle position.

If your tri bike has a76 degree seat tube angle you should be in a good position. Your saddle will be a inch or two in front of your road seat position because of a more slack road angle, Good luck!

Get your hip angle as close as possible on the two bikes, that will be the closest you can get to working the same muscles.