...Hey..... I like that part you brought the naija factor oo. Network network and bad network. This bad network stuff in the country is another thing especially if you are off network areas like major cities, you really go crazy sometimes thinking something had gone wrong with your wallet if you are waiting for an update.
The amount involved in transaction A and B won't be the headache of miners but how much fee involved, so they will keep dropping it to pick higher ones because there are transactions on the Blockchain to work with which was the reason they both landed in same block and I suspect it wasn't a peak hour.
This is the reason I believe it is faster, easier and luckier to get low fee transactions to be processed during off rush/ peak hours like night time and early morning...
You're right mate, poor network connectivity is a pressing issue we have in our country that should be tackled cause it has many significant consequences not only on our economy but socially as well. Anyways back to the subject matter, I've not experienced the situation the OP's explained but I have a clue and my own case is something almost similar due to poor network connectivity but in the P2P market, I opened a trade with a merchant in the P2P but experienced poor network connectivity when I was about to release the coin after the merchant made payment, I got many text from him after my network became stable, to him I was being deceitful little did he know that it wasn't my intention but due to a poor network connection. Concerning your last paragraph I think I do experience better network connectivity at night and early mornings too so for folks like me it would better to carry out transactions at those times.