Toilet venting question

We are doing a bathroom remodel and will be moving our toilet to where the current shower is. The toilet 3" line will flow past the current line for two sinks to join the main stack. All fixtures are more than 6' from the main stack. The current shower already has its own 1.5" vent and the two sinks have a 1.5" vent. Rather than put in a new 2" vent we we thinking of connecting the 3"pipe to both existing vents as this would provide more venting capacity than just one two " vent. Has anyone seen this done?

draw a sketch please

i think it all depends on the geometry that a sketch will show, what you mean by connecting, how, where, etc.