I think your Pediatrician is not a very good doc. Baby food and table food are much less healthy than formula or breastmilk. They have more fat, salt, sugar, etc.... If another Pediatrician gives the same advice then I would take their advice into consideration.
That said. I think a visit with a nutritionist might be a good idea. Obviously your baby is large. At 95% she is about double what her expected weight should be. Some people have more body mass, weight, than others. I have tiny bones but weigh a lot. As a child I was pretty thin, even up through high school. I expected my kids to follow the same path. I used to take care of a little girl that I would have put on a strict diet due to her being 2-3 years old and wearing a 6X. I made her a few things because she looked odd in clothes that were so long but smaller clothes would not fit around her. Her mom said every child in her husbands family were the same, they would shoot up around 7-8 and be normal size so she wasn't worried about it. I worried about it. Now the girl is 7 and looks completely normal.
I think your baby is too heavy for her development. I think it will hinder her to scooting and crawling if she is stays this heavy. The doc may have this in mind due. I think the baby needs to be on formula but adding in the cereal and gradually, SLOWLY, adding in other foods over the next 6 months can be good for her too. But not substituting the formula.
I think if I were you I would add a bit more water to the formula. Not much maybe put 6 oz. of water to the 3 scoops of formula and after it's mixed up well add maybe another ounce of water. That way she'll still be getting the nutrition of 6 oz. formula but getting a bit more fluid to fill her up.
If she needs to suck she'll find something to suck. If you have a pacifier then try it. If she needs to suck and doesn't find the right thing to such she'll start sucking her fingers or something available. Try some things out and see if it makes a difference. If it's just the sucking motion she needs then a pacifier is the best way for me instead of the bottles or a finger.....