Here are the portmanteau words formed from the provided words:
sheep + herder = shepherd (8 letters)
information + entertainment = infotainment (11 letters)
education + commercial = educamercial (11 letters)
Elbridge Gerry + list = gerrymander (8 letters)
pocket + monsters = pocket monsters (13 letters; however, if considering only 'pocket' + 'monster', it would simply be 'pokémon' which has 7 letters)
malicious + software = malsoftware (10 letters)
emotion + icon = emoticon (8 letters)
soy + milk = soymilk (7 letters)
plum + apricot = plucot (6 letters)
Please verify that the portmanteau words align with the expected combinations and remain within the specified letter counts.