"On one side some say fruits are better digested alone,"
This side does not have t2 diabetes. If they are, their glucose levels are uncontrolled and out of whack.
"on other side they are digested quite fast which may cause spikes in blood sugar)"
For a t2 diabetic it is best to eat fruits with other foods to slow the absorption of fructose [fruit sugar]. And, when it comes to fruits not all fruits are equal. Certain fruits have high fructose values such as pineapples, mangos, papayas, watermelon, apples, pears, including fruit juices and grapes and raisins. Be extra careful when eating these fruits as they can jack up your glucose levels, even with other foods.
Bottom line is to test, test, test and find out which fruits do or do not elevate your glucose levels. If unsure test again. Some of us cannot tolerate any fruit of any kind in any quantity so keep that in mind.
My experience is to not eat them period.