While you might get lucky, you're betting on the mainboard power delivery and cooling system to cope with a that additional load. 1 (additional-) port, yes - 2, maybe (probably), 4 has seen other boards (futro) crumble and crash - even more so if you go beyond 1000BASE-T, don't get too greedy (unless you're willing to risk defeat and hardware damage).
Don't get me wrong, it might work out well - but doesn't need to, so be aware of the risks and how far you can go without doing Russian Roulette.