HSMP Dependant visa - Sponsor Finances

Hi all

My brother is applying for his wife visa as an HSMP dependant.

He has very good permant job earning in the range of 40k and also have a house bought on mortgage, but he has only GBP1,500 in his current account as just 4 month before he got married and a bit earlier than that bought his house.

Is the current account statement showing ending balance of around that range would be enought for sponsoring the dependant visa. He is planning to submitt only three months bank statement (as in the statements before that have large outflows)

Please can anyone advise whether his finances is in reasonable range for sponsoring his wife visa and three months statement would be sufficient. We would very much appreiacte early respoonses.

Many thanks

any help please