Deeper, dynamic and realistic alliances

I think that the system of alliances should improve and be deeper, with more options, more realistic and dynamic (even though now it's pretty good).

For example, currently if an alliance is at war with another faction, when that faction calls for a truce, sometimes it's rejected by my allies (without me being able to do anything, even if I wanted to accept it) and other times I can accept or reject it without  furthers problems (feels arbitrary and with a lack of realism).

Another example of it: my alliance was at war with another, I had a fleet weakening the defenses of the capital planet of another faction, I spent a few turns doing this and just when I was about to capture it (for a Supremacy Victory), I discovered that I couldn't attack the planet, I couldn't understand the reason why, until I discovered that suddenly, I had a truce with that faction because my ally had accepted it (but I couldn't decide absolutely nothing and it spoiled all my strategy).
I think it would be more interesting if those decisions could be voted on.
Another option like just as allowing another member to join the alliance also should be voted on by all the members.
Just as in the governmental elections of the game, there could be a status for each member faction, marked by certain points based on actions taken during the alliance (or using dust, or influence) that would allow pressure to be put on other alliance members to make certain decisions.
This status of power and major influence would be gained for example by the relative power of each faction, battles won if there were a war, resources contributed to the alliance (each faction would contribute to the alliance with a certain percentage or impulse in science or industry depending on what they produce in their empires), or a common pool of resources and things like that. Even there could be a fleet create especific for the alliance. It would be interesting to vote for a leader for the alliance periodically (as in game elections) who would have more power to propose treaties or make decisions. 

More things could be allow, that a member may be expelled, if, for example, it attack to an empire with which the rest of the alliance had no problems or with which the rest had nice relations.
Allow a declaration of war on another empire or alliance to require a vote, which could be influenced by pressure depending on the status of that member in the alliance (think real world, not all countries have the same power or influence even if they are members of the same covenant or alliance).
I don't want to compare one game with another (both are two of my favorite games), they're totally different, but certain parallelism are inevitable, and I think that a deeper system like the one Stellaris uses would be something that would give the game more possibilities, to really face it from a more peaceful way, without resorting so much to battles.

This are just some ideas I like and want to share with you all.