No, because without tones it can be ambiguous even for native speakers. If you still don't believe me--or those Wikipedia links I already provided--you test it

No, because without tones it can be ambiguous even for native speakers. If you still don't believe me--or those Wikipedia links I already provided--you test it yourself by finding a native Mandarin speaker. Ask them to decisively determine the meaning and pronunciation of certain Chinese words only from their pinyin with the accents stripped out, such as ma or hua. There's a store with snacks and produce. Do you want to eat lizi, or do you want to eat lizi? (Don't bother squinting, it's the same letters.)