I looked at Arabizi and the numbers are really annoying for formal text etc. Finglish is better in my opinion, however it causes problems like being able to read the same text in two ways. like "dar". The a can be like 'a' in 'dad' or it can be 'a' like in 'car'. with different pronunciation it means 'door' and 'gallow' which can be very annoying in Arabic languages that unlike Persian write _ُ_ِ_ٌ_ً_ٍ_ّ_. Instead of numbers it uses combinations like 'kh' for 'خ', 'gh' for 'ق' and 'غ'. In some methods they use 'aa' for 'a' sound like 'bar' and single 'a' for 'a' sound like 'lad'.