The Golden Company comprising of 10,000 men, especially sellswords, are the largest force existing in Essos. Aegor “Bittersteel” Rivers, established this force while trying to stake his claim to the Iron Throne. However, he failed.
After his defeat, he flew beyond the Narrow sea and raised the Golden Company which also had various other Westeros exiled beings. Presently, the company members like to be known as a free brotherhood of those banished from Westeros, rather than sellswords. We first saw them brought up by Ser Davos during the fourth season at the time when Stannis Baratheon attempted to capture King’s Landing once again. Stannis didn’t want to use the Sellswords. However, Davos pointed out that they had never dishonored any contract.
Presently Cersei Lannister plans to use them for personal good. She tasked Euron Greyjoy to bring them back to Westeros. Daenerys Targaryen has vanquished her army, and now she has entered into a deal with TychoNestoris luring him with ample Gold.
There is no reason why they were brought back in attention towards the finale of the series, unless, they are going to be seen in Westeros in Season 8. Cersei Lannister aims to capture anything that’s not protected by Daenerys Targaryen. Still, she is more worried about the war that would follow. Is the Golden Company capable of defeating Daenerys Targaryen and her likely Northern allies?
Daenerys’s army primarily comprises the Dothraki, and then there are about 5000-6000 of Unsullied. Jon also has about a thousand strong troops of his own, and now all the important Northern Lords have also now pledged alliance with him. Therefore, he will have much larger numbers with him, and he also has the cavalry of the Knights of the Vale on his side. The Golden Company are foot soldiers themselves, and a good cavalry force can slice through swarms of foot soldiers.
That’s what Stannis did to Mance’s Army beyond the wall, and also we saw the Nights of the Vale destroy Bolton army in the same fashion.
There is another thing which makes the Golden Company powerful, and that’s their unknown number of elephants. A cavalry is not of much use against Elephants. Therefore, we might feel that the Golden Company is the advantageous force here. However, another thing that tips the scales is that despite their huge form, elephants are easy targets for archers and there are not many archery forces better than the Dothraki. Daenerys also has a couple of Dragons at her disposal, and the elephants won’t even be able to get anywhere near those Dragons.
Overall, we don’t think that the Golden Company can cause much damage to Daenerys Targaryen and her Army, in case they are intact after their battle against the Dead, that is.