Are you anticipating Italy being invaded by an army of mutated merman or perhaps some european yetis. Those threats being more likely than France, Britain or A-H being able to launch a meaningful offensive accoss the alps or naval invasion before 1915.
Conversely, in addition to Italy, A-H will be facing German, Russian and Bulgarian forces, and that's assuming those peace loving Serbians are not also in the mix. A-H will be going down faster than...
Why would the Alt Entente have to invade Greece, Bulgaria or Italy at all? After calling up soldiers, Italy was no longer sufficient for food. Italy also was not able to supply enough coal domestically and was dependent on the UK for
90% of their supplies. ITTL, Italy would have to be relieved relatively quickly or they would be forced to surrender. More likely, Italy would stay on the sidelines until A-H was decisively defeated and then join the war as a CP power.
Similarly, Greece was isolated and dependent on supplies that would be easily blockaded by the Entente. Again, Greece would either be starved out or remain neutral until after the war was decided.
Take a look at the railway connections in 1914 and you'll see that these peripheral countries could not be supplied before A-H was defeated as the Alt CP could not send supplies by sea in the Black Sea or the Mediterranean.