But that doesn't make sense, because she puts herself right on the front lines, repeatedly.
She personally handles the Eyir mission in Stormheim
naturally, enslaving eyir was critically important to sylvanas, she needs val'kyr of the 9 that made a pact with her, as of 8.1 only 3 remain, and if she dies one more time she will be left with none. not only that but she would need val'kyr to make new forsaken.
and if you want something done right, then you have to do it yourself, so yes sylvanas did have to put herself at risk, but the potential gain for sylvanas vastly outweighed the risk. with eyir enslaved she would access to unlimited val'kyr as she can just keep making more and more and more. she would pretty much be untouchable.
She leads the Horde attack at the Broken Shore.
remember why the legion was here, to burn our world. so if they succeeded sylvanas would die regardless of how large how bulwark is. the world would still burn. so sylvanas probably did not want to leave anything to chance.
She hunts Malfurion herself
again the reward outweighed the risk, if she killed malfurion, she could bring the war of thorns to an easy close and use the occupation of teldrassil to splinter the alliance which was the original plan. this would have put her in less harm than what we are seeing now.
She leads the counterattack in the BfA cinematic.
i question how canonical since we play through the battle of lordaeron but never see her take the front lines. in fact the only time we see her put herself in any risk is at the end, because she was luring them in for a trap to try and kill off the alliance leadership but most importantly, she had an out
but lets pretend the cinematic is canonical. sylvanas may be undead, but she still understands some living concepts like morale, and morale is very important to win battles which she definitely wants, it would be a morale boost to see your warchief lead at the front.
what we are seeing as that sylvanas mainly only puts herself at risk if the risks help secure long term safety for herself.
but she isn't a coward and she cares for her people, in her way.
i dont doubt that she cares for her people, but the way she cares about them is vastly different than how anduin or genn care about theirs.
to put it simply she cares about her people in the same way i care about my swords. they are a tool that is useful to me but if my swords broke i would simply replace them if i could not repair them. the same applies to sylvanas, if 200 forsaken were slaughtered and their corpses burned by the alliance, sylvanas will shed no tears over them. she will simply shrug and raise 200 more to replace them.