intelligent load balancing issue

Have a look at this one and let me know what out of this doesnt work for you and we can modify this,  I tested this one below and it works. Ignore the wildcard as thats not your case

And what modifications are needed ... i am yet to explore policies equivalent of I-rule but i can try modifying the Irule

ltm rule pool_URI-redirection {
when HTTP_REQUEST {
switch -glob [HTTP::uri] {
"/URI1/v1.0/RMAOrders*" {
pool pool_pool_5101
}
"/URI1/v1.0/miscIssues*" {
pool pool_pool_5085
}
"/URI1/v1.0/miscReceipts*" {
pool pool_pool_5084
}
"/URI1/v1.0/pickReleaseOrdersAck*" {
pool pool_pool_5083
}
"/URI1/v1.0/poReceipt*" {
pool pool_pool_5081
}
"/URI1/v1.0/purchaseOrdersAck*" {
pool pool_pool_5079
}
"/URI1/v1.0/purchaseOrders*" {
pool pool_pool_5078
}

"/URI1/v1.0/RMAReceipts*" {
pool pool_pool_5111
}
"/URI1/v1.0/shipConfirmOrders*" {
pool pool_pool_5076
}
"/URI1/v1.0/subInvTransfers*" {
pool pool_pool_5077
}
"/URI1/v1.0/pickReleaseOrders*" {
pool pool_pool_5082
}
"/anotherURI/Endpoint*" {
pool pool_pool_5115
}
}
}
}