Some Ashkenazim are medakdek to pronounce their Aramaic "correctly". And they know that there is a mapik heh in Amein Yehei ShemeiH Rabba. Thus, יְהֵא שְׁמֵ*הּ* רַבָּא מְבָרַךְ לְעָלַם וּלְעָלְמֵי ...
If you are late to Maariv and miss barchu and you normally daven slowly should you... Daven faster, even if it means saying the words with little to no Kavana so that you can say Barchu at the end. ...