Not the same at all but ... you assume all can-kickers are only after more money? Is that the only reason a player would ever be unhappy at a club?
Fair point about trying to replace a player 2 weeks out, but do you think clubs only ever try to shop players with plenty of notice?
Aside from your rare marquee type star, clubs hold all the aces in terms of bargaining power. This is the main reason behind the emergence of a class of dishonest manipulative opportunistic greedy amoral (but otherwise decent) player managers - an attempt by players to get a little more balance in the relationship with employers.
all that doesn't change the one fundamental difference ... one side is guaranteed full value of their contract ... the other side is being denied theirs ...
and no ... don't assume, that I assume players only leave for more money ... but generally if the player has a legitimate reason for wanting out ... eg family and compassionate reasons ... the clubs in recent years have been mostly accommodating .... allowing for negotiation of swap deals and timing etc