needing advice on solids!

Audrey
I'm just out of my baby's 5 month checkup. The pediatrician talked about introducing solids but here is his take on it :
Veggies can only be introduced one at a time always with potatoes. First a small amount of the vegetable mixed into the potatoe purée and then moving to being half vegetable and half potatoes.
Fruits can only be introduced one at a time always with apples. Small amount first into applesauce and then moving to being half any fruit half apple. 
We have to feed about 120 - 150 grams of purée instead of a bottle around noon. We can add a baby yogurt to complete the meal.
Then at 5 and a half month we'll introduce the snack around 4pm with a fruit purée and we can complete the meal with a yogurt. 
At 5 month and a half, you add cereals to the last bottle of the day. 1 dose of cereals for 8 days and then 2 doses.
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The food schedule 
1- morning
 1 bottle with if we want 2-4 teaspoons of cereals 
2- noon
120 grams to 200 grams of vegetable purée. + 1 yogurt or 1 small jar of fruit purée 
( after 5 and half month, add meat to the vegetable purée)
3 - snack (4pm)
1 bottle or 1 yogurt + 1 fruit purée or biscuits (at 8 months)
4 - evening 
1 bottle with 1 dose of cereals. Then 2 doses.
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First I have never heard or read anything about always needed to have apple or potato as the base of the purée... Even in store bought baby food there isn't always potato or apple, I just don't get it. I do plan on making my own baby food but still, how could that possibly work for people who aren't stay at home moms and who need to buy baby food..?!
And this is the paper the doctor gave me, fully knowing that right now my baby is exclusively breastfed and that I'm not switching to bottles any time soon.
This is so not designed for my baby it almost makes me angry!!
So I needed you guys advice and guidance on this.. :/