AVMutableVideoCompositionLayerInstruction translate scale rotation

Question

I am using AVMutableComposition to merge/stitch multiple recorded video tracks and save it like this expected output

..so I am looping through the subviews to transform each tracks according to each subview size.

    var index = 0
    for subview:UIView in template.subviews {
        let scaleX = (subview.frame.width / template.frame.width) / (tracks[index].naturalSize.width /  mainComposition.renderSize.width)
        let scaleY = (subview.frame.height / template.frame.height) / (tracks[index].naturalSize.height /  mainComposition.renderSize.height)
        let x = subview.frame.origin.x
        let y = subview.frame.origin.y

        let rotate = CGAffineTransformMakeRotation(CGFloat(M_PI_2))
        let scale = CGAffineTransformMakeScale(scaleX, scaleY)
        let translate = CGAffineTransformMakeTranslation(x, y)
        let transform = CGAffineTransformConcat(scale, translate)

        let transformation = AVMutableVideoCompositionLayerInstruction(assetTrack: tracks[index])
        transformation.setTransform(CGAffineTransformConcat(rotate, transform), atTime: kCMTimeZero)
        instructions.append(transformation)
        index++
    }

The problem is that the videos are all out of placed in the saved video. But without the rotation, I am getting the expected output like in the attached image but with the videos in landscape - which i read that is always the case for captured videos in iPhone device (how to export video asset via AVAssetExportSession in portrait mode)

I have been playing with CGAffineTransform, rearranging translate, rotate, or scale on which goes first or last but not getting good result. I have also tried creating two layerinstruction separating the rotation and sctaletranslate but still the same.

Thanks for any help

Torhert