Lady Zhurong is by far the most underappreciated & most misunderstood hero in the game despite being one of or if not the most versatile one.
I will try my best to explain how I found she is best utilized.
First of all u should know that despite her usefulness it is very unlikely to achieve any contribution titles with her even though u are often the person on the battlefield that tactically seen does the most. The reason for that is that she is not strong in any particular way nor is she weak in one, she is mediocre in every way but that is where her versatility comes in play. She can fill almost any required position on the battlefield, be it archer, warrior or even anti-cavalry.
At the beginning of every match I would suggest to start out as an archer & try to harass the enemy as much as possible until the match-up of the battlefield becomes clear to u & u know what role u should fill in for.
Although she comes in handy for almost anything that is required on the battlefield, her & her units arrows are what do most of the damage in most cases. Of course her units melee is quite good as well, it is usually better to deal damage without receiving damage urself until u have absolutely no choice but to engage in a melee fight. Her hounds can also be used to harass & damage the enemy. Afterall they are respawnable with 40% focus so it is free damage without any risk.
In most cases u will want to try to be the last of ur teams unit left on the battlefield after most of the brawling is done simply because 1v1 she can grind down most units rather easily.
Of course the units u should pay the most attention to, are archers because whilst ur units can shoot arrows themselves u cannot send volleys in a specific direction like u can with normal archers. Most of the time ur units will shoot at whatever is closest to them. However if u can manage to properly position ur units so they will target archers, u should do so as they will make quick work of any non-shielded units.
If u notice any melee unit charging u just command ur hounds to intercept them with F7. While they do so u can take them out rather easily if u still have enough arrows in ur unit or in the worst case u can just escape. Escaping is something that often even works when an enemy melee unit is already close to u because ur units can run much faster than almost any other infantry in the game.
If cavalry charges u, u should try to stand close to obstacles that will block them (such as walls or edges). Most of the riders will run against the obstacle & get stuck, meaning ur units can quickly dismount them & finish them off.
If u have the rage % for it always try to use the feral rage ability of ur hounds for extra damage. It will inflict bleeding onto enemies which causes damage over time.
Also dont forget that u can place a bear trap with ur Q ability. It will damage & stagger up to 10 enemies when it is triggered. I found that its most useful when used in an offensive way rather than preamptively as a defense. Its radius is rather small & unless placed in a choke point its impossible to be sure that the enemy will run into it.