Why are you comparing apples to oranges?
1. This so called banks profits in kenya are just a symptom of a serious crisis, these banks are the major lenders to GoK. Its a despicable business where they borrow from central bank then lend to Gok. Something that Magufuli himself said is unacceptable, - He would rather let those banks die.And even to a layman, this is pure BS.. Banks exist to lend to people and businesses, not to fleece treasury coffers..though the ever bankrupt Gok is a very willing albeit stupid borrower.
2. Tz economy by GDP PPP is bigger than kenya, income equality is among the best in africa. Wholesale importation of manufactured goods from kenya is at an all time low since Tz is now firing up its industries and eating up kenya market share with its low industrial production costs. Cherry picking small data points to support your predetermined notion is not the practice of economists..You have to look at the whole picture.
3. If there is anything that Tanzania can do now is to obtain Foreign Capital to build infrastructure and lend to local manufacturers, that is the missing link. Tz is now a middle income country and has shown ability to payback huge loans. the only caveat here is not to borrow stupidly with hubris like kenya. Tz GDP is at $60b with 27% Debt to GDP, kenya was at GDP $60b in 2015 and their hubris Debt to GDP was at 40%. Tz has a better growth base and an even better debt ceiling compared to kenya - Thats how you analyse an economy.