There's no difference between the requirements for ICAO Level 4 in English, Spanish, French, German or any other ICAO recognised ATC Language.
The important thing is that you can use standard ATC Phraseology making your pronunciation and delivery clear and concise.
You'd be suprised how many non native speakers who can communicate in almost perfect English at normal conversational level, but only make level 4 or 5 when it comes to Aviation English (or other language)