Is it possible to update BQ aquaris E4.5 with latest firmware for BQ aquaris A4.5 I have this phone, BQ Aquaris E4.5
https://tweakers.net/pricewatch/434564/bq-aquaris-e45-ubuntu-edition-zwart/reviews/

And at the moment I have android 5. 
However I want to update to Android 6.

On the official page of the manufacturer I see http://www.mibqyyo.com/en-download/categorias/aquaris-e4-5/

However I see update for BQ Aquaris A4.5

http://www.mibqyyo.com/en-download/categorias/aquaris-a4-5/

Do you think If I try to update the firmware, the phone will break ?

Regards,
Oleg
If the specs from PDAdb is to be believed, the 2 phones are quite different hardware-wise:

BQ Aquaris E4.5 Dual SIM vs. BQ Aquaris A4.5 4G LTE Dual SIM

The A4.5 is a relatively new Android One phone that's promised 2 years of support. The E4.5 on the other hand, despite released in late 2014, bears a MT6582 SoC which had fallen out of mainstream for quite some time. There's no way you could cross-flash between these two, and you likely won't find anything tailored to this particular device either.