I think you are OK on the length.
The back says to work to 15 and a half inches.
The front says to work to 14 inches.
I can see a tension gauge for stitch count but not one for row height so I cannot work out for you if these 10 rows difference would be roughly 1 and a half inches but I’m going to guess that it is.
You can measure the back to check the length and measure the front to check the length, expecting a 1 and a half inch difference.
You may also already know your row gauge either from a swatch you have done or you can measure rows on the sweater and see if 10 rows is 1 and a half inches.
Some patterns have the back neck higher up than the front (even without the collar addition) so that it fits well and doesn’t sag backwards.
Please can you remove the pattern photos due to designer copyright. if you click the little pencil icon at the bottom of your post you can edit the post and just delete the photos.
Do you think you can manage section of the pattern now?
It’s ok if you have more questions.