You got to look at structure of the SAA.
And you have to realise that things have changed; it's 2017 now and the war started in 2011. Over time, through a very painful learning process the Syrians as a whole have improved and of course they have benefited from outside advice. This is not to say that there are no inept Syrian and inexperienced units led by equally inept and inexperienced officers but as a whole they have improved; if they hadn't their front lines would long have collapsed, even with Iranian and Hezbollah help.
If you look at the size of the country and the many areas or front's there are; it's obvious that the Iranians and Hezbollah can't be everywhere once; even if they significantly increased their numbers and are able to sustain those numbers logistically and financially. The fact remains that the bulk of the fighting is still done by Syrian units - not all of which are ''elite'' [a term you're fond of using] and there have been tactical successes in areas where there was no or minimal Iranian or Hezbollah participation. It's not as if Iran and Hezbollah have deployed a few divisions worth of troops which are deployed on every corner of the battlefield.
Here what's going on the SAA regular unit are nothing but conscript which we already know some went AWOL and other switch to FSA and Jihadists.
In the early days of the conflict desertion was a major issue but over time desertion is not the major issue that it was in the early days. In fact, there have actually been reported cases of rebels [we assume non IS] deserting to the Syrians and as some tend to forget, Assad's forces contain quite a number of Sunnis as well. If the bulk of the Syrian army was made up of conscripts who were just waiting for the apt time to desert, the army would have collapsed a long time ago.
Syrian High Command must be given credit for where they put the regular SAA unts at the right place.
I believe in giving credit when due : the Syrians [despite past and continued cockups] appear to be [as expected given that they've had quite a while to absorb some lessons] doing some things right. We also have to ask what the motivations of the average Syrian soldier are. For the Alawites [not all of whom are dedicated Baathists] and the other minorities who have stood by Assad it's the knowledge that a IS victory would be disastrous; given how IS has treated non Sunni and also Sunni prisoners. For the Sunnis it's a bit harder to explain their motivations but we can presume that they feel that Assad represents the lesser evil and that they don't subscribe to IS's warped ideology.
[State-Of-The-Art Technology Gives President Assad’s Army The Edge
http://www.independent.co.uk/news/w...president-assad-s-army-the-edge-a6898741.html
[Syrian Soldiers On The Latakia Front Finally Taste The Fruits Of Victory - But They Know Isis Is Not Dead]
http://www.independent.co.uk/news/w...y-russia-turkey-al-rabiaa-assad-a6882281.html
['An Army Boot Is Placed On The Face Of The Dead Men': General Ghassan Of The Syrian Army On The War Against Nusra]
http://www.independent.co.uk/news/w...n-of-the-syrian-army-on-the-war-10289588.html
The Iranians and Hezbollah are discipline soldiers which at time causes them to hit hard which result in high deaths.
Overall the high rate of death among Iranian and Hezbollah is due to depending on SAA for other tasks which they are not capable of handling example is artillery.
Being discipline doesn't equate to being effective on the battlefield : one can have ''discipline'' units that are also tactically inept. Just like how the failure to observe parade ground formality in the field doesn't mean an army lacks discipline.
The high casualties suffered by the Iranians and Hezbollah are probably caused by various factors; namely the way they have been employed and also because they do not know the area or local surroundings as well as the Syrians. As I've pointed out before, when it comes to actual combat experience [which doesn't automatically equate to battlefield effectiveness] the average Syrian unit may actually have more experience than their Iranian and Hezbollah counterparts.
Questions that remains unanswered but ones that are essential to form an accurate analysis is statistically how do the losses suffered by the Iranians and Hezbollah in Syria compare to what they've suffered in Iraq and [rather than just assuming they're ''elite''] how much experience does the average Iranian and Hezbollah fighter actually have? We also have to keep in mind that the average IS fighter may not be necessarily more competent or experienced that his enemies. Sure, IS has a cadre of experienced fighters but also has its share of fighters who lack experience and training and who rely more on belief in ideology to produce results.
The SAA artillery are just plain garbage.
Maybe, maybe not but if I were on the receiving end of arty it wouldn't matter to me if those doing the firing didn't have the skills of an average American or British battery. Also, we have to look at the type of fire missions being conducted. No doubt Syrian artillery doesn't come up to Western standards but then it may not have to; especially if the targets being fired at have long been pre-registered, are under direct observation, are not mobile, are not time sensitive and are located at a safe distance from friendly troops.