Many our companions what Inquisitor have as options does not have sense to be his companions rather then just agents of Inquisition and some agents have sense to be our companions
Dorian(exile who is not even a magister or member of a imperium circle, its a pity that Felix dies and not him). Blackwall(who is noone and not a real greywarden officer, and lelianna even know it). Sera. Cole have zero sense to be Inquisitor companion, they are noone and not valuable to be them
Vivienne have some amount of loyalists mages and some political influence, she is optional, she is more uselfull as Vinn was for Grey warden still not as valuable as Fionna
Bull have a mini army of mercenaries and he is spy from Qunari who give us info, he is optional, even have a role in main story-treespacer and his fate have influence on many Tal-Vashots
Still...
Cassandra is undestandable as our companion before we become Inquisitor and have skyhold, but after, especially after we have OUR alliances,OUR peoples and may have not tolerate with her opinion it would be better if we have option to get rid of her and especially Cullen with Lelianna....if we are pro-mages and non-human non-chantry Inquisitor it make sense, we even destroy seekers with lord seeker Lucius, she have nothing
especially of getting rid from Cullen as "our" general, he is really not deserve that role where he was putted to be templar knight commander and general for no reason and not suited to command army especially many types of ous different(mages,nonhumans, non-templars) alliances, it would be best if we have him as companion-advisor if we choose Templars as our alliances and Fionna(she have a very good experience of warfare and commandership since greywardens where she was a high ranking officer, and in politics too) if mages
It would be better if we have Varrick as our advisor on diplomacy rahter than useless antivan Josephine or he can do a spy thing, and Brialla with her army spies what was clearly better and she as bards spymaster have more personal experience and agents than ex-minor bard and ex-dead divine spy Lelianna by her own without Inquisition, Inquisition would win more with Brialla as spymaster rather than Lelianna, even Varrick was better as spymaster then her
DAO was better on companions and their sense to be companions as with their valuable, DA2 too
DAO have only Zevran as useless and nonvaluable to be a Grey Warden companion, others have a weight(what we can know or not but stull have as divine spy Lelianna or Sten what we can not have and miss in game at all) to be our companion exept dog what can not count as companion
DA2 have only fenris
DAI have plenty of guys who is not where they need to be and many of them are forced to be with us no matter what even that was not make sense
we can even say to Cassandra and Cullen that we are with Inquisition not need them but they kinda pretend that they are not listen and have a reason to stay, they stay even after we deal with Coryfeus for 2 years...others are go away and those are not but we have all power and influence