These guys are great and well loved. MC Hammer pants, big shoulder pads, gleaming white armour and a honking great sword, what more could you want?
Our Myrmidons, being mostly a hybrid of mêlée and shooting, lack the serious grunt that other factions can bring from their 'jacks and beasts, especially in a bang for buck sense. Having Sentinels really covers that weakness, and they can be used for running a Secondary Jack.
Whilst not quite as renowned as the Sentinels, this is a solid unit. The UA [unit attachment, which is an Officer and a Standard] turn them into something a bit more offensive [a full unit of them on the mini-feat turn can mulch a Heavy] but generally they are a solid unit, a bit more defensive than the Sentinels, but this can be a good fulcrum for other units to work off.
This Solo is a high ranking knight. Unfortunately, his rules require a bit of a dance to get the most out of him, as it has to be done in order. Not highly regarded, though not terrible. Better choices are out there.
Mage Hunter Assassin.
A ninja elf ready to behead the baddies Caster? - brilliant! The MHA has a fearsome reputation, in being quick and killy. The thing is, they are actually quite dice'y, meaning they are not something to hang your hat on. But because of the high potential they have, they can really cause a headache for your opponent, who will be nervous about the MHA having an attack run on their Caster, Solo or even 'jack. This in itself can be game-altering.
Our mêlée specialists are generally very good, barring the Scyir. As WM is mostly about movement and combat, these choices will nearly always be a solid choice for a RoS player.