Getting repeat skills when leveling up

[sita999]

I notice that along the right hand path of the levelling up tree, where the skill choices are, choice 1 and 3 are the same e.g., tanks can choose from armored or disciplined in their first and third choices. If I make the same choice both times, does it increase the chances of the skill happening? If so, anyone know if it's an additive or multiplicative increase?

Edit: I just did some testing, before and after adding a second specialization in armored. With only one specialization in armored, the armor fired off 7/50 times. After adding the second specialization, it fired 24/50 times.