But the only difference is that Slovianski doesn't have verb forms that don't exist in Slavic language. So if you speak one of the slavic languages, you don't need to learn all the forms, you have already got them "with your mother's milk".
The same with irregular verbs idet' and moc'. In Slovio you have to remember always: "Idit is REGULAR verb, so I must write "Ja idel"!" Using Slovianski you don't have to think about that, you use the forms that you use in your everyday life.