Aerolineas Argentinas has a 4.2/10 rating on Skytrax, so is that a plus or a minus for SkyTeam?

believe it or not they are a lot better now. Their domestic fleet is quite modern and they are in the process of an upgrade of their international product.

You mean their domestic fleet got a paint job? Looking at the engines on the picture at this article they look from another era. ;) Ofcourse domestic flying is far worse with the cowboys of Air Austral!

Well considering that IB score 3.1 and AA 3.3 and even BA only manage a 5.8 on Skytrax, it does not say much for Oneworld, three of the biggest carriers in that alliance with very poor scores.  Those Skytrax ratings you take with a pinch of salt, very few of the reviews offer constructive feedback

Skyteam are being very strategic with airlines they are incorporating.  They have been very focused on emerging markets like China, Indonesia, Asia in general and South America and including airlines who are undergoing complete revamps of their aircraft, product and service like Garuda and Aerolineas

Both airlines were terrible but both are undergoing complete overhauls, Garuda is in line for major expansion and now offer a very high quality product and service on new aircarft.

Aerolineas are going through the same process and will re emerge a very different carrier in the future. China Eastern are also focused on raising the product and service on their international flights, they too have a long way to go