Is correlation causation here or not? You see, here you say the winning team is going to get the ocean and cloud drakes and the losing team wont contest.
you say the losing team will attempt to dive and steal mountain and infernal drakes in order to try to either stall or turn. but referring back to your first point, the winning team is most likely to get the dragon in the first place. which means statistically speaking you yourself pointed out that the majority of dragons taken are most likely going to be by the team that is going to win.
This in theory should atleast mean that if MOST dragons are taken by the winning team you can atleast infer from the data taken from the dragons taken by winning team, which dragons which team they had when they won, and scrape together numbers on what dragons are LIKELY the biggest factors in that win.
if you collect data from 100 million games ( a number easily achieved by riot), and more teams won with wind and cloud drake than with infernal and mountain, it would be safe to at least assume if not state outright that these dragons are possibly the most influential in a game. if you claim that it's only worth stealing mountain and infernal dragon, then you would generally assume that in 100 million games played and 100 million cases of losing teams placing higher priority in securing these dragons in order to stop themselves from losing, that these dragons had in fact the power to generate this turn around.
instead, in 4 dragons (excluding elder), mountain and infenal dragon took the bottom two slots in highest win rate. because losing teams fought for a dragon that didnt help them win. they "gave away" dragons they thought werent of benefit and gave free power to their enemies, and fought for a dragon that wouldnt save them.
so yeah. looking at that data, i would say damningly that mountain and infernal dragon are the worst dragons in the game, because no one gets a monopoly and no one gets to use them to win. everyone is so worried about the 2 perceived "strongest" dragons in game they give their enemies free power and dig their own graves. anyone who denies numbers from literally hundreds of millions of games of collected data just because they want to think their own opinion of the strongest dragon in game is what is true (as is happening in this thread), is why those two dragons dont win games. because they let the enemy win by only caring about their coveted golden children.