D&D 5E Can you delay your attack to perform and bonus action attack?

[wrandalljr4]

Hello

Horde Breaker: Once on each of your turns when you make a weapon Attack, you can make another Attack with the same weapon against a different creature that is within 5 feet of the original target and within range of your weapon.

Great Weapon Master: On your turn, when you score a critical hit with a melee weapon or reduce a creature to 0 hit points with one, you can make one melee weapon attack as a bonus action.

Can you choose which order to do your horde break? Let's say you are surrounded by 3 foes. 2 side by side and 1 behind you.

1 - In your first attack, you hit and kill one of the targets that were side by side (Within 5 feet of each other). Which triggers your horde break. So now there are only 2 foes standing.

2 - but instead of attacking with the same weapon against a different creature that is within 5 feet of the original target and within range of your weapon. You use your great weapon master ability to use your bonus action to attack the for that was behind you and not within 5 feet of another target.

3 - After the attack, the foe behind you and is not within 5 feet of another target, can you now choose to use your delayed horde break action on the other foe who during your first attack had another target beside them, but no longer does because you kill it with your first attack?

I hope I explained this correctly.

 

[Shiroiken]

None of these things specifically states when you have to perform the attack, simply that you can once you fulfill the requirement. You could attack the rear foe with your Bonus Action attack, then return to perform your Horde Breaker attack. It's not a logical situation, since it would seem like you should perform the Horde Breaker attack first, but it's not mechanically required. Of course, I see little benefit for choosing the order you suggest, unless you have a specific benefit to "your next attack" that you want to use against the rear foe.

 

[Plaguescarred]

Horde Breaker attack can only be made against a creature within 5 feet of the original target.

I am not sure of the exact positioning you're referring to but if the 2 creatures side by side are are adjacent and the one behind you is not, when you kill one of the 2 side by side, Horde Breaker's attack can be used on the other one side by side since it's within 5 feet of the original target, this wether you kill the one behind with Great Weapon Master's attack or not.

But if you kill the other side by side with Great Weapon Master 's attack first, then Horde Breaker's attack cannot be used having no creatures within 5 feet of the original target left to attack.