I was browsing juuku and I found the sentences:
From this I assumed that, when the quantity of comparison (年齡）has been fixed, I am free to choose whether or not to add the corresponding adjective （大） after 一樣。
But when I presented the following sentences to native speakers, there was no agreement, as to whether the 高 was superfluous or not：
我跟他身高一样高 / 我身高跟他一样高。
Can you enlighten me, preferably citing from some book?