How come? A more fusional language is one where a single word can carry more forms of information where English would need more words (e.g. "my book"). This isn't directly related to how much information you should put in a sentence. OTOH, all languages are recursive which means you can construct arbitrarily long sentences - but you shouldn't, because human cognition has its limits.

In my experience as a speaker of a more fusional language, the sentences are shorter than in English, not longer.