Arri Alexa is a dilemma now.
If used in controlled environment, lighting can be adjusted to lower the hdr and gels can be used to get different colors. Alexa is not critically needed.
If used in uncontrolled news shooting run-u-gun environment, Alexa is too unwielding, even the Amira.
Arri Alexa was acclaimed due to several major camera shoot out tests happened in 2010 2011 2012. Those test environments emphasized on extreme scenarios that hdr is the single most important criteria. Even Sony F35 and Red One/Epic failed. In reality, Both are nice cameras.