Is the source of Sheikh Ibn Baz's fatwa regarding the compilation of the supplications for entering the mosque the same as the source of your website's fatwa concerning the combination of the different narrations of the opening supplications in prayer?

The scholars of the Sunnah (definition) have differed concerning the opening supplication (Du'a al-Istiftah). Some are of the opinion that the worshipper should recite one narration at times and another narration at other times, and should not combine two or more narrations in a single prayer. This is the view preferred by Sheikh Ibn Baz and Sheikh Bakr ibn Zayd. Others are of the opinion that it is desirable to combine the narrations of the reported supplications at one time. However, it is better to restrict oneself to a single form of the opening supplication in one prayer. As for what is outside of prayer, such as entering the mosque, the matter is broader.