Protein is protein whatever form it comes in and you need between 0.8-2 grams of protein per kilo in body weight in order to build a lean muscular body. For example if you weigh 100kg or 225lbs you should be having between 80-200 grams of protein daily. The more active you are , the more protein you require.
Here is a list of clean vegan ingredients high in protein that you should incorporate into your diet to build bigger stronger muscles.
4-pulses, grains lentils etc
6- walnuts, almonds, cashews
7-greens asparagus, kale, rapine
10- fruits a variety of tropical colorful fruits
There are lots of other great protein sources for vegans. This is just an example of ingredients you should incorporate daily into your diet.